Ferrari’s Charles Leclerc edged Red Bull’s Sergio Perez by just 0.006 seconds in Friday practice at the Azerbaijan Grand Prix.
Leclerc’s time was set late in the session, when the track would have been quicker than for some of his rivals, after a difficult day that included a crash in the first session.
Mercedes driver Lewis Hamilton was third fastest, 0.066secs behind Perez, ahead of Ferrari’s Carlos Sainz, McLaren’s Oscar Piastri and Red Bull’s Max Verstappen.
McLaren’s Lando Norris, Verstappen’s closest challenger in the championship, was 14th fastest after being held up by Pierre Gasly’s Alpine on what would have been his fastest lap.
Leclerc came into the weekend arguably as favourite for pole position, having qualified at the front three years in a row in Baku.
But he crashed his Ferrari halfway through the first session, and while it was ready in time for the start of the second hour, Leclerc was quickly complaining that something was wrong.
Ferrari told him they could see nothing on their telemetry data, but he said the car felt “not straight” and he needed to come in to the pits, saying: "It's impossible you cannot see that on the data."
That put him out of sync with the other drivers and meant he did his qualifying simulation run on the soft tyre later than his rivals, which in theory is an advantage.
Red Bull look much more competitive than they did in Monza two weeks ago, but Verstappen, after setting the pace in the first session, did not have such a happy time in the second.
He complained about understeer - a lack of front grip - as he has done at many recent races, and had both a near-miss with the wall after misjudging Turn Five and then a trip up the escape road at Turn Three.
The Dutchman, 62 points ahead of Norris with eight races remaining, ended up 0.545secs off the pace.
Norris appeared set for a time that could have challenged Perez at the top until he was blocked by Gasly coming through the flat-out kinks on the pit straight and had to back off.
On race pace, the McLaren, in Piastri’s hands, appeared to have a slight edge on Perez’s Red Bull.
George Russell was another to have a difficult session. He was late out after Mercedes discovered an engine problem and then was called in before the end with another unspecified issue. He ended up ninth fastest.
Oliver Bearman, standing in for the suspended Kevin Magnussen at Haas, was 10th fastest, two places and 0.072secs behind team-mate Nico Hulkenberg.