Lando Norris Edges Out Piastri in Sao Paulo Practice
The British driver has beaten his teammate at each of the past five race weekends.
Lando Norris just pipped team-mate and title rival the Australian for the fastest time in the dying seconds of the practice session at the Sao Paulo Grand Prix.
Norris, who took the points lead from his teammate by a single point after taking the win in Mexico City recently, topped the Melbourne-born driver by a tiny margin of 0.023secs.
Before then, Piastri had been the quickest of the McLaren pair during the running before sprint qualifying set to begin at 18:30 GMT.
Max Verstappen, the other racer in the points battle, trailing 36 points behind behind Norris, ended up in 17th position as his Red Bull team followed a different programme.
Verstappen's team-mate the Japanese driver was the only driver to go off, albeit lightly, when he rotated at corner four soon after starting.
The Japanese lost control over the track edges before spinning across the gravel trap, and was fortunate to escape with just a minor contact of the fence.
The Ferrari of Lewis Hamilton also lost it, at the conclusion of the session, turning around through the quick descending Mergulho corner approaching the last turn on to the start-finish straight.
Hamilton ended the session in P19, one place behind team-mate Charles Leclerc.
Norris and Piastri were well clear of the other competitors, with Nico Hulkenberg's Sauber P3, 0.619 seconds off Piastri's best.
The Aston Martin of Fernando Alonso was fourth quickest, with the Sauber of Bortoleto in front of the Mercedes of George Russell and the Alpine of Pierre Gasly and Williams' Carlos Sainz.