BARCELONA, Spain (AP) - Ferrari driver Felipe Massa was fastest in the third and final practice session for the Spanish Grand Prix on Saturday, edging Lotus' Kimi Raikkonen by .006 seconds.
Times started to drop after the medium tires came out late in the session, and Massa took advantage to clock a fastest lap of 1 minute, 21.901 seconds in mostly sunny conditions.
Red Bull driver Mark Webber was third quickest, just in front of Romain Grosjean for Lotus. Three-time Formula One defending champion Sebastian Vettel was fifth for Red Bull, one place ahead of two-time F1 winner Fernando Alonso of Ferrari.
McLaren's struggles show no signs of ending, however, with Jenson Button and teammate Sergio Perez outside of the top 10 places for the second straight day.
The top six drivers were separated by only .353 seconds, suggesting qualifying later Saturday will be close. The race is Sunday.
Massa has started every race in the top five this season, but Ferrari is looking for its drivers to find extra speed in qualifying following three frustrating seasons to increase the pressure on Red Bull.
The closest Ferrari has been to pole position this season was when Massa qualified second at the Malaysian GP in March. Teammate Fernando Alonso has started the last three races from third spot on the grid, and he will hoping for a higher position in front of his home fans on the Circuit de Catalunya.
Raikkonen will be looking for a third consecutive podium finish after opening the season by winning in Australia despite starting from seventh spot.
Grosjean has had a frustrating start to the campaign, although his form picked up with a third-place in Bahrain.
Mercedes has been fast but lacking durability so far this season, but Lewis Hamilton and Nico Rosberg stayed on longer runs than any other driver in completing 50 laps between them.
Having set the early pace on hard tires, Vettel will need to pick up the pace in the afternoon to earn a third pole of the season after starting top of the grid in the first two races. The German has won twice so far this campaign.
Following on from Friday's two underwhelming practice sessions, McLaren's prospects still look gloomy. Button was 1.25 seconds off the pace in 12th place on Saturday, while Perez was 1.472 back in 14th.