Valtteri Bottas edged out Lewis Hamilton in opening practice for the Japanese Grand Prix.
The Finn, who trails Hamilton by 73 points in the championship with five races remaining, finished just 0.076 seconds clear of his Mercedes team-mate at the Suzuka circuit.
Ferrari's Sebastian Vettel ended the first running in third, one second off Bottas' pace.
The drivers will contest only two practice sessions after Saturday's action was cancelled due to Super Typhoon Hagibis.
Final practice has been axed, while qualifying will now take place four hours before Sunday's race.
The Mercedes cars have led the way in Japan in recent seasons, winning every race at Suzuka since 2014.
Bottas and Hamilton, who will win the world title in Mexico in a fortnight's time if he outscores his team-mate by five points over the next two rounds, enjoyed a comfortable advantage over the rest of the field, dominating the first running here.
Japanese driver Naoki Yamamoto was awarded his first drive of a Formula One car by Toro Rosso, and finished 17th of the 20 runners.
Earlier, F1 bosses and the sport's governing body, the FIA, announced the Suzuka circuit would be closed on Saturday due to the typhoon.
The move came a day after England's Rugby World Cup match against France on Saturday was cancelled in response to the approaching storm.
A statement issued by the FIA read: "As a result of the predicted impact of Typhoon Hagibis on the 2019 FIA Formula One Japanese Grand Prix, Mobilityland and the Japanese Automobile Federation (JAF) have decided to cancel all activities scheduled to take place on Saturday, 12 October.
"The FIA and Formula One support this decision in the interests of safety for the spectators, competitors, and everyone at the Suzuka Circuit."
The region's most powerful typhoon of 2019 is set to bring violent winds and heavy rain to the area.
The race in Japan has been hit by bad weather in the past, with qualifying staged on Sunday morning on two occasions, in 2004 and 2010.
Four years ago, qualifying for the US Grand Prix was pushed back a day due to heavy rain.
"I am happy for them to do that," said Lewis Hamilton, who holds a 73-point championship lead over Mercedes team-mate Valtteri Bottas with 130 available.
"It is cool when the format changes. You have to enter into two different mindsets, and two different rhythms. It is a different challenge so I like that.
"It is intense here when it rains, but I love driving in the wet. It doesn't make a difference to me. It is quite exciting."
