Aston Martin's Fernando Alonso topped the timesheets ahead of Ferrari ace Charles Leclerc in a rain-hit second practice at the Australian Grand Prix on Friday, but world champion Max Verstappen went fastest for the day.
The Spanish veteran followed up his podium finishes at the first two races of the season in Bahrain and Saudi Arabia with another eye-opening run.
He powered around the bumpy Albert Park circuit under darkening clouds before rain fell in a best time of one minute 18.887 seconds among his 13 laps, bettering his fourth place in the first one-hour session.
"The afternoon was obviously impacted by the rain, so there is still some work to do tomorrow," said Alonso.
"We need to learn more about the tyres and the long-run pace of the car because there was not much time for that today. So far though the car seems to behave well."
Leclerc, who won in Australia last year, came an encouraging second after Ferrari's early season reliability and pace issues, nearly half a second adrift but ahead of Verstappen.
The Red Bull pilot, the early championship leader, clocked a 1:18.790 in the first practice when he had an out-of-character spin, which was better than Alonso's second session best.
But the Dutchman had no decent opportunity to improve on it on a wet track, saying it was slippery and he had low grip.
"It was difficult to tell how the car felt as we never got a window where I thought we were on top of the tyres," he said.
"We'll look over the data tonight and see what we have to do tomorrow. The conditions should be clearer for the rest of the weekend, so we can focus on that."
- Not so good -
Red Bull are attempting to score a third consecutive 1-2 finish for the first time in the team's history in Melbourne after their dominance in Bahrain and Saudi Arabia.
Verstappen's teammate and Jeddah winner Sergio Perez came seventh.
Seven-time world champion Lewis Hamilton was a surprise second in the opening practice but could only manage a disappointing 13th in FP2.
"This morning was good, but this afternoon wasn't as good," the Briton said.
"We made some changes after FP1 that didn't quite work and we will look to revert this evening."
His teammate George Russell was fourth ahead of Ferrari's Carlos Sainz, with Alpine's Esteban Ocon sixth.
McLaren's Lando Norris, Haas driver Nico Hulkenberg and Pierre Gasly in the other Alpine rounded out the top 10.
Williams' Logan Sargeant, who had an electrical problem during the first practice, failed to complete a lap.
As in FP1, Sainz was first out and set the early pace before Verstappen, who made his debut at the 2015 Australian GP as a 17-year-old, quickly took over to power clear.
But his reign at the top was brief, with Alonso posting a sizzling lap and Leclerc also bettering him before light rain began falling and the umbrellas went up in the grandstand.
Virtually all the cars headed back to the pits with 40 minutes remaining after Norris ran onto the grass at Turn 1 when his grip failed and Lance Stroll tapped a wall in his Aston Martin.
The drizzle eased and several cars headed back out, including Sainz and Leclerc.
But they didn't last, with Leclerc saying on the team radio "there's no point driving like this".
Others ventured out to test the waters later, primarily to gather data, but no one improved their times.
The forecast for Sunday's race is dry.
In an eventful first practice, Haas's Kevin Magnussen and Alpha Tauri's Yuki Tsunoda both skidded into the gravel. The Japanese star hit the gravel backwards and narrowly avoiding the barriers.
There were some close calls with that session red-flagged for safety reasons due to GPS issues, with teams not able to monitor car position.
It was halted again when Sargeant stopped on the track with just minutes remaining.