Championship leader Lando Norris topped the times for McLaren in first practice for the Japanese Grand Prix on Friday as Yuki Tsunoda impressed on his Red Bull debut with the sixth-fastest lap at the Suzuka circuit.
Norris twice had to abandon his flying lap and went off the track into the gravel at the final chicane on his 12th, but came out of the pits after a switch from medium to soft tires to set a time of 1 minute, 28.549 seconds.
Mercedes driver George Russell had been the front-runner for much of the session on a sunny day at Suzuka but had to settle for second place ahead of the Ferrari duo of Charles Leclerc and Lewis Hamilton in third and fourth.
All eyes were on Japan's Tsunoda, however, as he enjoyed his first session in the Red Bull after being promoted from the Racing Bulls team at the expense of Liam Lawson last week.
The 24-year-old took little time getting used to his new car and was in second place after his quickest lap before being overhauled by the leading quartet and his teammate Max Verstappen later in the session.
Crucially, though, Tsunoda was only a tenth of a second behind the four-time world champion, a marked improvement on the pace managed by New Zealander Lawson in the first two races of the season in Australia and China.
Lawson, back at the Racing Bulls team, was only able to manage the 13th-fastest time and was outpaced by his French teammate Isack Hadjar, who was eighth fastest behind Aston Martin's Fernando Alonso.
Norris' McLaren teammate Oscar Piastri, the winner in China two weeks ago, was a disappointing 15th fastest, while the second Mercedes of Kimi Antonelli managed the ninth-fastest lap despite a late detour into the trackside gravel.
Second practice for Sunday's race takes place later Friday with a third session Saturday before qualifying.