F2 champion elect, Charles Leclerc, served notice to his bosses at Ferrari today that he is ready to make the move up to F1 as soon as possible, topping the timesheets on the first day of the second in-season test.

The Monegasque driver, running on soft rubber, posted his best time (1:17.746) - which would have been good enough ninth in Q3 last weekend - in the final moments of the session, eclipsing the previous best, set by Stoffel Vandoorne, by 0.088s.

With Ferrari likely to retain Kimi Raikkonen alongside Sebastian Vettel next year, the most likely scenario will see Leclerc join Sauber as opposed to Haas, the Swiss team having agreed a new deal at the weekend which will see it use the same spec engines as the Maranello outfit next year.

Over the course of the day, the 12 drivers on duty completed 1,111 laps, Mercedes fielding two cars - one for Valtteri Bottas to carry out 2018 tyre testing for Pirelli - and Nikita Mazepin and Lucas Auer sharing duties at Force India.

It was a difficult day for Red Bull, with Verstappen appearing just before the lunch break after encountering engine issues. While the Dutch youngster had a busy afternoon, concentrating on long runs, he finished over 3.48s off Leclerc's pace.

Vandoorne who stopped out on track in the final moments before lunch, causing widespread deja vu when his McLaren stopped on track, missed the first two hours of running in the afternoon as his team worked on the problem.

While Bottas completed 155 laps for Pirelli and Russel 119, it wasn't an entirely trouble free day for Mercedes which suffered a repeat of the radio issues that plagued the team during Sunday's race.

DTM racer, Lucas Auer, nephew to former F1 star Gerhard Berger, made an impressive F1 debut, completing 54 laps in the afternoon and posting a best time 2.8s off the pace.

Along with F2 and GP3, F3 was well represented today, with former competitors Russell, Leclerc, Stroll, Ferrucci and Malja all in action.

Being a test for the cars, not just upcoming (and established) drivers, there was plenty of flo-vis throughout the day as well as sensors. While Williams, where Stroll replaced an unwell Massa, is understood to have been trying a number of changes to the FW40, and Leclerc tried a new diffuser on the Ferrari.

98 laps at the wheel of the SF70H in the boiling heat of the Hungaroring and a final lap time of 1:17.746, on the soft tyres, but for Charles, the stopwatch readout was not the most important aspect of this day.

"Driving a Ferrari is never a 'normal' experience," said the 19 year old. "I felt as though I was driving a race car for the very first time. It's a great honour I have been accorded and I thank Ferrari with all my heart for this opportunity.

"I am pleased with the work I did and I hope the team is too. Driving the SF70H was a fantastic feeling and coming from F2, it's a whole other world, from every point of view. It was the first time that I've driven a Formula 1 car with the wider tyres and this level of aerodynamic downforce and it was an incredible feeling. I also learned a lot from the work in the garage: Ferrari has the best engineers in the world and I felt very comfortable working with them.

"To set the fastest time is nice, but, in testing, its importance is only relative. I can now go on holiday in a happy mood, before concentrating on the second part of the F2 season. For the moment, Formula 1 is just a dream. I still have work to do and I know that: one step at a time."

At McLaren, in the morning session, the team focused on a number of shorter runs, running through rapid set-up changes and aero correlation tests between laps for swift evaluation. Later on, Vandoorne began some longer runs, again focusing on evaluations of chassis handling and stability.

Shortly before lunch, after he had completed 35 laps, the team stopped the car out on track as a precaution due to a suspected fluid leak, which brought out the red flags. The team did a thorough check of the chassis and power unit, and the leak was traced to the engine. Although time-consuming to locate and rectify - necessitating removal of the power unit for checks - the issue was not serious, and Vandoorne was able to return to the track shortly after 16:00.

For the remainder of the afternoon, the team focused on further balance, handling and set-up changes with a variety of short runs on different tyre compounds and fuel-loads. Stoffel completed 72 laps and ran with good pace throughout the day, topping the timesheets shortly before lunch, where he stayed for the majority of the afternoon session before dropping down to second in the dying moments.

"It's actually been a very productive day for us, despite the stoppage," said Vandoorne. "We've put some new things on the car to explore throughout the day and I feel they've been positive - we've definitely moved in the right direction as the day has progressed.

"It's good to see that when we bring new parts to the track, they respond and improve the performance of the car. Obviously, this is testing, and it doesn't mean a lot, but it does give us useful data that we can analyse and help our learning. We have a busy programme over these two days and hopefully after the summer break we can show that we've made another step forward and make further improvements for the rest of the season.

"A test after a race weekend is always very valuable for the team, and provides a good opportunity to validate things that did or didn't go well, and introduce new parts that might have been too much of a risk during the sessions. It's been a pretty good week for us in Hungary, and positive to be consistently running in the top 10. I hope tomorrow goes well with Lando and we can gather more useful data, before the team starts a well-deserved summer break."

"Although today was relatively stop-start in terms of both the types of short-run evaluations we've been conducting, and a couple of reliability glitches, we still managed to complete a good proportion of our run-plan and gathered some very useful data that will prove very valuable as we continue to develop our package for the remainder of the season," said Eric Boullier.

"Stoffel acquitted himself very well as always, and provided a lot of thorough feedback that will help shape our run-plan for the final day of the test tomorrow. With a 35-degree ambient temperature and around 54 degrees on track, the conditions were particularly tough on the car today, but we were still able to take some valuable learnings from the various tests we completed.

"Tomorrow we welcome Lando Norris into the car to experience his first outing in the MCL32, while we continue with our scheduled test programme."

"Today the team used the extra track time to try some new parts for the chassis," said Satoshi Nakamura, "while we tested some new elements on our power unit. The aim was to collect precious data, and to work on improving both performance and reliability for the second half of the season.

"We had an oil leak issue just before lunch, and lost some track time as a result, but we're not too concerned -I'd rather find these problems during testing, and the issue itself wasn't serious.

"Stoffel maintained the momentum from his first point-scoring race of the season at the weekend, and posted the second-best lap time of the day - he was just pipped at the end of the session.

"Tomorrow we'll continue with our programme and try to make as many gains as we can before the summer break."

While Bottas carried out testing duties for Pirelli, for the first time ever, George Russell was behind the wheel of the W08, ending the day in P4, clocking a 1:19.231 on the supersoft compound in the afternoon.

Today's programme mainly focused on aero testing items for correlation with a vibration logging programme and some brake system work.

Bottas completed 155 laps for the Pirelli programme on 2018 Slick tyre development.

"Today was incredible," said Russell. "I have been looking forward to this day for so long. It's every young driver's dream to drive a Formula 1 car. As soon as I got on track, I straightaway understood how much grip and downforce this car has got - it is amazing. 48 hours ago I was driving a GP3 car around the same track, but today was totally different. Luckily for me I had done lots of simulator work with Mercedes, so I knew what to expect.

"The biggest difference is the power steering in the Formula 1 car, and I could feel that as soon as I got out on track. And the braking potential is enormous. I was expecting the speed on the straight and the downforce in the corners, as everyone does. But I don't think anyone quite understands the braking power of this machine.

"In GP3 we enter into Turn 1 at about 260 or 270 km/h, braking at the 100 metre board. Today, I was going in at almost 300 km/h, braking 25 metres after what I would do in GP3. Today mostly consisted of longer runs with higher fuel loads. We wanted to see the degradation of the tyres, and mainly trying to work for the race simulations. I was quite happy with my performance. For my first time in the car, completing 119 laps and not being far from Valtteri - I'm pretty pleased with that."

At Williams, where Lance Stroll stood in for Felipe Massa, the Canadian completed 138 laps on his way to posting the 5th best time of the day.

"We completed a lot of tests today," said Rod Nelson, the Grove outfit's Chief Test & Support Engineer, "completing 15 runs and 138 laps. We worked on mechanical set-up and some set-up directions that we've been developing through the day, which is very interesting.

"We also did some systems work for the future, which we hope to bring racing at some stage in the season, and we put some miles on components that, again, we hope to be racing in the near future, so a pretty successful day. There were quite difficult conditions as it was relatively cool this morning but then it got pretty hot by the middle of the morning. It's quite difficult to get the best out of testing in those kind of conditions but I think we did a reasonably good job and as usual, we've got masses of data to trawl through to get some results out of."

"We tried some new stuff and it was good to have more time in the seat," said Stroll. "It was warm, it was a hot day and it's physical around here so it's good training. We need to see if what we tested here today works in Spa, we need more running with the new parts to see if they work but Spa should definitely suit our car with longer straights so I'm looking forward to it."

Check out our Tuesday gallery from Hungary, here.