Australian debutant Oscar Piastri has endured a challenging and eventful Formula One bow at the Bahrain Grand Prix.

The 21-year-old McLaren driver finished 12th in morning practice and 15th out of 20 in the afternoon in what proved tough debut sessions on the Bahrain International Circuit on Friday.

In the morning, the Melbourne man oversteered on one corner and had to come off the track before regaining control.

Then in the second session, in which conditions were more representative of what he'll face in the race itself on Sunday, he also locked up and ran wide after only his quick thinking and lightning reactions enabled him to avoid a collision.

Alongside Yuki Tsunoda in the AlphaTauri, Piastri was trying to overtake when Lance Stroll's slow-moving Aston Martin in mid-track provided him with another obstacle which he negotiated by swiftly taking evasive action, swerving to his right to avoid rear-ending the Canadian driver's car.

The incident resulted in Piastri locking up and running off the track at the first turn.

Ultimately, the Australian negotiated the rest of the session with no further alarms, clocking up a fastest lap of 1 minute 32.024 seconds, which was 1.117sec behind the surprise leader on the timesheets, Aston Martin veteran Fernando Alonso.

More pertinently for the newcomer, he was just under half a second slower than his British teammate Lando Norris, who after a fifth place finish in the morning was ninth in the second session, 0.663sec down on Alonso.

Watching the team's new boy in action, McLaren CEO Zak Brown told Sky Sports that he was not worried by the big time margin between the teammates.

"They're on similar programmes. Oscar needs to get his racecraft going. It's early in the season, obviously, and he's got a pretty tough teammate in Lando, so there's no concern at all.

"Oscar's doing exactly what we want him to do, which is just get some laps in and get familiar with the car.

"So far, things are going well, the drivers are happy with the car, so hopefully we can get into Q3 (the third qualifying session on Saturday to find the top-10 drivers)."

When Piastri had lost control of his car on turn seven in the morning session to leave the track briefly, his engineer asked over the radio, "Is the car all okay?"

To which the man from Melbourne responded, "Yep, all okay, just had a snap".