Nico Rosberg heaped the pressure on Mercedes teammate Lewis Hamilton by scorching to the fastest lap in second practice for the Singapore Grand Prix on Friday.
Hamilton had two sessions to forget as he could only come fourth in the first 90 minutes of running and seventh in the second, before having to pit early with a hydraulic problem.
Rosberg's flying lap of the 5.065 kilometre (3.14 miles) Marina Bay circuit in 1min 44.152sec enabled him to bounce back after crashing in the first practice session earlier in the day.
Formula One supremo Bernie Ecclestone and Chase Carey of Liberty Media, the sports new chairman, arrived at the track in time for second practice and would have liked what they saw at the spectacular night event set against the skyscape of downtown Singapore.
Sunday's race is shaping up already into a three-way tussle between Mercedes, Ferrari and Red Bull after Kimi Raikkonen was second fastest in the Ferrari, just 0.275 sec behind Rosberg.
Then came the Red Bull of Max Verstappen, using a new upgraded Renault engine, just ahead of his teammate Daniel Ricciardo.
Last year's winner Sebastian Vettel was fifth quickest in his Ferrari.
Rosberg is just two points behind championship leader Hamilton after back-to-back wins in Belgium and Italy.
Victory in his 200th grand prix start on Sunday would put the German back on top of the standings he had led at one stage by 43 points earlier in the season.
But Mercedes, despite being the dominant force in Formula One for the past three years, traditionally struggle on the slower street circuit in Singapore which negate their power advantage.
They didn't make the podium in Singapore last year as Vettel won ahead of Ricciardo.
The Red Bulls were thought by many in the paddock to be favourites for Sunday's race with their emphasis on mechanical grip and downforce.
And they looked the men to beat as they had a one-two in the first practice session on the fastest ultrasoft tyres.
But Rosberg's run in the second session will have given Mercedes hope for Saturday's qualifying though Hamilton's lack of track time will have denied him valuable set-up preparation for the race.
Hamilton retired in 2015 after qualifying only fifth and Friday he was complaining over team radio of fierce heat in his car's cockpit in both sessions before having to park early in his garage.
"It's hot on the right side of the cockpit," Hamilton complained.