SEPANG, Malaysia -- Heavy rain halted proceedings for much of the first practice session for the Malaysian Grand Prix before Max Verstappen ensured Red Bull finished the on the top of the timesheets when the chequered flag fell.
Fifteen minutes before FP1 began, light rain started to fall on the Sepang International Circuit but it quickly intensified forcing race control to delay the start of the session. For 30 minutes the only track action was that of the Mercedes AMG Safety Car completing reconnaissance laps to assess the conditions.
When the pit exit finally opened it was Fernando Alonso and the Ferraris of Sebastian Vettel and Kimi Raikkonen who first ventured onto the track. It wasn't until the final 30 minutes that drivers started setting lap times, by which point the track was dry enough for intermediate tyres.
Verstappen, who once again demonstrated his class in wet conditions, set his benchmark time of 1:48.962 in the final 10 minutes. The Dutchman finished 0.7s ahead of Red Bull teammate Daniel Ricciardo in second.
Despite completing just six laps, three of which were with the Halo head protection device fitted, Alonso finished third quickest for McLaren, ahead of the Ferraris who waited until the final minute of the session to post their most competitive laps. Raikkonen finished ahead of Vettel, albeit 1.7s down on Verstappen's time. Constructors championship rivals Mercedes were next in line with Lewis Hamilton finishing sixth and ahead of teammate Valtteri Bottas.
Lance Stroll showed decent pace for Williams to end the session in P8, edging out race weekend debutant Pierre Gasly. However it wasn't such a great morning for teammate Felipe Massa who failed to set a lap time after suffering a suspected hydraulics issue.
The Renault pair of Sergey Sirotkin -- who was sitting in for Nico Hulkenberg -- and Jolyon Palmer finished in 10th and 11th. In the second McLaren, Stoffel Vandoorne struggled to replicate the pace of his teammate and ended the session 12th.
Force India struggled for competitive lap times with Esteban Ocon almost five seconds off the pace in 13th while Sergio Perez settled for 15th. They were split by Toro Rosso's Sean Galael, who was driving Carlos Sainz's car during the morning session.
The rain-interrupted session means we are no closer to learning who the team to beat this weekend in Malaysia is. Teams will hope conditions improve for FP2 which gets underway at 15:00 local time.