Piastri led his McLaren teammate Lando Norris to the tune of just 0.032s in the opening hit-out at the Emilia-Romagna Grand Prix.

A meagre 0.096s covered the top five with Norris followed by standout performer Carlos Sainz (Williams), George Russell (Mercedes), and Lewis Hamilton (Ferrari).

Just shy of full-time in the 60-minute session, Sauber’s Gabriel Bortoleto lost control of his car at the penultimate turn. The Brazilian slid off the road and into the tyre barrier.

That brought the sessions to an early end with just two minutes left on the clock when the red flag was drawn.

It was a clumsy start to the session for Charles Leclerc, who put his Ferrari off the road at Acque Minarali. As he slowed to clean his tyre, Fernando Alonso arrived quickly in his Aston Martin at the Variante Alta chicane.

“I nearly crashed with Leclerc,” Alonso complained on his radio, prompting FIA stewards to put the incident under review for impeding.

It wasn’t long after that Leclerc was off the road again, this time in the second part of the Variante Alta chicane as he suffered understeer.

Leclerc wound up 12th at the end of the session, half a second off Piastri.

Initially, it was Norris who set the pace but that was quickly beaten by Mercedes lead George Russell, who at halfway sat atop the pile on a 1:16.599s.

Just shy of halfway, Verstappen shot to second for Red Bull but was pipped shortly thereafter by Sainz. After Verstappen came Alpine’s Pierre Gasly and hometown hero Kimi Antonelli in the second Mercedes.

🚩 RED FLAG 🚩

Bortoleto into the barriers. He's okay 👍#F1 #ImolaGP pic.twitter.com/FNjTyIIO9Q

— Formula 1 (@F1) May 16, 2025

Ferrari continued to wobble. Lewis Hamilton cut the Variante Alta chicane at the 29-minute mark. Meanwhile, Leclerc complained of his helmet lifting at high speed, forcing the team to install a larger windscreen on the SF-25.

Piastri fired to the top of the pile just after halfway with a 1:16.545s to edge Russell by 0.054s. That time would stand as the benchmark to the end of the session. Norris responded with a little more than 20 minutes to go, coming within 0.032s of the Australian.

Verstappen’s session was turbulent from start to finish. He wound up seventh and 0.360s off Piastri’s pace. The RB21 looked a handful for the four-time champion who was visibly frustrated, banging the steering wheel in the closing minutes of the session.

The Formula 1 Emilia-Romagna Grand Prix continues with Free Practice 2 at 1am AEST on Saturday.

Results: Formula 1 Emilia-Romagna Grand Prix, Free Practice 1