Lewis Hamilton puts Mercedes on pole position for the Spanish Grand Prix with a fourth successive win beckoning.
Championship-leading team mate Nico Rosberg, who is four points clear of Hamilton, qualified second with Australian Daniel Ricciardo starting third for champions Red Bull.
Williams' Valtteri Bottas and Lotus' Romain Grosjean were fourth and fifth ahead of Ferrari drivers Kimi Raikkonen and Fernando Alonso.
Grosjean'splacing is comfortably the team's best qualifying performance of the year after a difficult start to the season.
The team have been battling reliability problems after a late start to pre-season testing but after making progress in the first four races are finally in a position to exploit the car's potential.
McLaren's Jenson Button was eighth ahead of the Williams of Felipe Massa. Red Bull's Sebastian Vettel was 10th, failing to set a time in the top 10 shoot-out after his car lost drive coming out of the pits at the start of the session.
"It's been a tough day," Hamilton said. "Nico has been driving really well so I didn't know whether I'd be able to get it. But right at the end I managed to get absolutely everything out of the car."
Hamilton, celebrating his fourth pole of the season and 35th of his career with a time 0.168 seconds quicker than the German, will take the overall lead in the standings if he wins at the Circuit de Catalunya.