Ahead of today's opening session, the air temperature is 27 degrees C while the track temperature is 42 degrees.

As one would expect, in the aftermath of testing the teams have introduced a number of upgrades... some more than others.

Red Bull has a revised Floor Edge, Front Wing and Coke/Engine Cover, Ferrari a new Front Suspension, Front Wing and Engine Cover.

Mercedes has a new Front Wing Endplate, Rear Wing, Nose, Floor Edge, Sidepod Inlet and Front Suspension, while Alpine has a new Front Wing, Nose, Front Suspension, Front Corner, Floor Body, Engine Cover, Rear Suspension, Rear Corner, Beam Wing and Rear Wing.

McLaren has a new Front Wing, Floor Body, Front Corner, Sidepod Inlet and Engine Cover, Cooling Louvres, Beam Wing and Rear Corner, while Alfa Romeo has a new
Front Suspension, Floor Body, Halo, Sidepod Inlet, Engine Cover, Rear Corner, Rear Suspension and Beam Wing.

At Aston Martin it's a new Front Wing, Front Wing Endplate, Front Suspension, Floor Fences, Floor Body, Floor Edge, Diffuser, Sidepod Inlet, Engine Cover, Cooling Louvres, Rear Suspension, Rear Corner, Beam Wing, Rear Wing and Rear Wing Endplate.

Haas has a new Nose, Front Wing, Front Wing Endplate, Front Suspension, Floor Fences, Floor Body, Front Corner, Cooling Louvres, Diffuser and Rear Suspension, while AlphaTauri has a new Nose, Front Wing, Front Suspension, Front Corner, Floor Body, Floor Edge, Diffuser, Sidepod Inlet, Engine Cover, Cooling Louvres and Rear Wing Endplate.

Finally, at Williams, it's a new Nose, Front Wing, Front Suspension, Front Corner, Engine Cover, Rear Wing, Beam Wing, Halo, Floor Fences, Rear Suspension, Rear Corner, Front Suspension, Floor Edge and Diffuser.

The lights go green and Albon leads the way, followed by his teammate Sargeant, Bottas, Zhou, Norris and Piastri.

Ocon's Alpine is sporting a massive aero rake.

Surprisingly, one of the last out is Stroll who is yet to drive the Aston Martin in anger.

As more drivers head out most are on the mediums, though Sargeant is on hards and the Haas pair on softs.

Verstappen and Stroll finally head out, leaving the Mercedes duo as the only no shows.

Of the first wave, Alonso (35.048) goes quickest, ahead of Perez, Gasly, Sainz and Piastri.

Finally, Hamilton heads out.

A wobble is followed by a quick excursion for Piastri at Turn 7.

As Perez improves to 34.343, Verstappen goes third and Hamilton fourth.

"I can smell something burning on the first lap," reports Sargeant.

As is ever the case with these evening, night-time events, in many ways this session is pretty redundant in terms of qualifying and the race, however with the lack of testing it offers another hour of data acquisition and trialling parts.

A very wobbly rear wing, smothered in flo-vis on Leclerc's Ferrari.

On the softs, Magnussen goes fourth and Hulkenberg seventh.

Russell's first lap sees the Briton go ninth.

"The pedals feel quite different to last time," claims Zhou.

After 25 minutes Stroll has yet to post a timer and has only completed two laps, but it's an issue with the car rather than the youngster's wrists. According to the team it is an ignition related issue.

Half-an-hour in and some drivers switch to the softs. Perez is one of them and immediately posts a 32.758, while teammate Verstappen, also on the softs, posts a 33.375.

Alonso goes wide in Turn 4 as Zhou continues to complain about his pedals.

Stroll heads out again on mediums.

Following all that wobbling, Ferrari has reverted to the same (double) rear wing mounting as his teammate.

Norris momentarily brings out the yellows when he runs wide in Turn 1 after missing his braking point.

A 360 at Turn 9 for Sainz, the Spaniard caught out by the same bump that caught Piastri and several others last week.

"Just let me drive the cars," snaps Stroll when given info on brake balance.

"I have to box, something's changed," says Sainz following his spin.

Leclerc fears an issue with his clutch, despite which he improves to fourth (34.257) on the mediums,

Alonso goes second with a 33.196 on the softs, just 0.438s off Perez' pace.

Norris improves to fourth with a 34.165.

Stroll posts a 34.298 on the softs to go sixth, which is pretty good, considering.

"We are happy with the session so far," Zak Brown tells Sky Sports. "Listening to both drivers they are definitely happier with the car than they were at testing, so it looks like we are making some forward progress.

"As you know with these cars they are never perfect, so I wouldn't say we have anything solved, but we are making a step in the right direction.

"Predictions are always tricky especially this early in the weekend, but I think we will put a better performance than we did in testing. Q3 is going to be tight because the midfield is so compressed, but let's see."

The session ends. Perez is quickest, ahead of Alonso, Verstappen, Norris, Leclerc, Stroll, Magnussen, Zhou, Bottas and Hamilton.

Russell is eleventh, ahead of Piastri, Tsunoda, Hulkenberg, Ocon, de Vries, Gasly, Sargeant, Albon and Sainz.

Check out our Friday gallery from Manama here.