Norris Leads Piastri in Brazilian Practice Session
The British driver has beaten his teammate at all of the last five race weekends.
Lando Norris just pipped team-mate and championship contender the Australian for the top spot in the final moments of practice at the Sao Paulo Grand Prix.
The British racer, who took the points lead from Piastri by one point after his victory in Mexico City a fortnight back, topped the Melbourne-born driver by a tiny margin of 0.023secs.
Until that point, Piastri had been the leading McLaren during the running before sprint qualifying due at 18:30 GMT.
Max Verstappen, the other racer in the championship fight, trailing with a 36-point deficit behind Norris, ended up in 17th place as his Red Bull team opted for a alternative strategy.
Verstappen's team-mate the Japanese driver was the sole competitor to go off, if briefly, when he spun at the fourth corner early in the session.
Tsunoda lost control over the track edges before sliding over the escape zone, and was lucky to get away with just a minor contact of the barrier.
The Ferrari of Lewis Hamilton also lost it, at the final moments of the session, rotating twice through the quick descending Mergulho corner before the last turn on to the start-finish straight.
The veteran ended the session in 19th place, one place behind teammate Charles Leclerc.
The McLaren pair were well clear of the remaining drivers, with the German's car P3, 0.619secs slower than Piastri's best.
Aston Martin's 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 the Williams of Sainz.
