Qualifying finished almost an hour later than scheduled after heavy rainfall delayed a red flag-packed Q1 by 20 minutes, but it was a yellow flag in the final moments of the afternoon that proved decisive.
Nine of the 10 Q3 drivers embarked on their second flying laps at once, creating a heightened risk of an incident with the potential to undermine the shootout for pole.
Fernando Alonso delivered on that risk when he spun his McLaren in the second sector. Hamilton, who was close behind the Spaniard, had his run neutralised by the resulting yellow flag, as did Red Bull Racing’s Daniel Ricciardo.
Rosberg, however, arrived at the affected area moments before it turned green, meaning he had to slow for just two yellow flags and was still able to set the fastest middle sector nonetheless.
The difference in conditions on Rosberg’s lap opened the door for an easy pole position, which he took with a 0.143-second advantage.
“It was a really challenging qualifying,” Rosberg said. “The conditions were changing all the time; it was really exciting out there.
“I just got a really good lap in on that last lap, so awesome, I’m very happy with that.
“I’ve been feeling really good out there the whole weekend, even with high fuel on Friday. I look forward to the race and a great opportunity tomorrow.”
Lewis Hamilton, who had been out of sorts all weekend and had crashed in free practice two on Friday afternoon (July 22), felt he had the speed to compete for pole position.
“I don’t know how much Nico was up, but I was four tenths [of a second] up,” he said.
“I felt good on the lap – a bit unfortunate with Fernando, but these things happen.
“I’m not too disappointed. It was s tricky session and I did the best I could do.”
Red Bull Racing and Ricciardo were a surprise package for qualifying after looking a distant half-second off the pace on Friday.
The early mixed conditions advantaged the team’s high-downforce car, but it looked equally happy on the rapidly evolving dry circuit at the end of Q3.
Ricciardo felt he was in the hunt for his second pole position of the season before yellow flags undermined his lap.
“I was pretty angry on that last lap because I was up a bit and I think it would’ve put me closer to pole,” he said.
“At the same time I think the session went really well. I think in all conditions we were really competitive. It was fun, it was challenging.”
Max Verstappen was unable to set his final flying lap after he set too slow a warm-up lap and missed the end of the session, but his first hot lap from earlier in the session was still fast enough to fend off Sebastian Vettel’s Ferrari for fourth place.
Ferrari has been disappointed to find itself off Red Bull Racing and Mercedes’s pace this weekend, and Vettel’s 0.3-second gap to Verstappen and 0.9-second deficit to pole will do nothing to liven the mood.
Carlos Sainz qualified an excellent sixth, but the Spaniard’s performance was overshadowed by the presence of both McLaren drivers qualifying in the top 10 for the first time since the team renewed its partnership with Honda last season.
Alonso qualified ahead of Jenson Button despite his spin, and the world championship-winning teammates put themselves ahead of Nico Hülkenberg’s Force India and Valtteri Bottas’s Williams.