Piastri improves on his latest time to move up to eighth overall, 1.6s on Sainz's earlier time.
Sainz, Verstappen, Albon, Zhou, Russell, Hulkenberg, Gasly, Tsunoda, Piastri and Drugovich.
Mick Schumacher is following proceedings from the back of the Mercedes garage in his new reserve driver role for 2023.
An update on how things stand after two hours of running in Bahrain, with Carlos Sainz at the top of the timesheets.
All 10 drivers now have a laptime on the board after Felipe Drugovich sets his first timed lap, following Aston Martin's early dramas.
Mike Krack: "Felipe stopped on track due to an electronics issue that has now been resolved."
Mercedes admin reveal #F1#F1Testing@MercedesAMGF1pic.twitter.com/eLRH5uTzrt
— Formula 1 (@F1) February 23, 2023
Sainz goes 0.3s clear of Verstappen at the top of the timesheets.
Again, times don't mean too much at this stage given we don't know the fuel or engine settings being used.
The reigning champion is back on top - less than a tenth ahead of Albon.
Former Mercedes teammates Lewis Hamilton and Valtteri Bottas were pictured having a catch up ahead of the pre-season photoshoot.
Albon takes to the top with a 1m33.671s, 0.096s ahead of Sainz.
The Spaniard sets a 1m33.767s to go 1.1s clear of Verstappen at the top of the timesheets.
Verstappen's best time is now a 1m34.895s, 1.1s clear of Gasly.
Verstappen extends his early advantage over the rest of the field to 1.4s by setting a 1m35.655s.
Hulkenberg is in second ahead of Russell and Sainz.
Nine of the 10 cars are out on track, with just Drugovich in the pit lane after causing the red flag.
F1 cars back on track
— Formula 1 (@F1) February 23, 2023
You love to see it! #F1#F1Testingpic.twitter.com/Qb8nfafYZG
First car on track in #F1Testing. pic.twitter.com/l0aUhJNFBc
— Mercedes-AMG PETRONAS F1 Team (@MercedesAMGF1) February 23, 2023
The session will resume in five minutes - 7:30am UK time.
The first shots of Max Verstappen & RB19 on track in Bahrain #F1Testingpic.twitter.com/PoSD24zvGR
— Crash F1 (@CRASH_NET_F1) February 23, 2023
Drugovich's Aston Martin is still being recovered.
Current order is: Verstappen, Russell, Sainz, Tsunoda. No one else has set a lap time.