Heikki Kovalainen finished quickest in practice for the first time this season to suggest McLaren might avoid being also-rans during Sunday's Turkish Grand Prix.

Fernando Alonso finished a mere six thousandths of a second behind Kovalainen in his Enstone-built Renault, followed by a return to form for Robert Kubica in his BMW Sauber.

Remarkably, further underlining the increasingly competitive nature of the teams this season, the top 16 were covered by 0.709secs.

After a miserable race in Monaco in which Kovalainen retired after seven laps following an accident and world champion Lewis Hamilton finished 12th and a lap down on race winner Jenson Button, McLaren headed into this weekend with a reputation to re-build.

After Hamilton concluded the initial 90-minute run second quickest behind Williams' Nico Rosberg, Kovalainen went one better in what was a tricky afternoon session for the majority of the drivers.

The Finn's time of one minute 28.841seconds for the Istanbul Otodrom was also the best of the day, bettering Rosberg's effort by just 0.111secs.

Williams' Kazuki Nakajima was fourth in the afternoon, with the Red Bull of Sebastian Vettel fifth, despite the fact he only managed four laps. The 21-year-old German was forced to stop on track after feeling what he described as "a huge vibration" in his car, diagnosed as a driveshaft failure.

Jarno Trulli was sixth in his Toyota, another team looking to up the ante after their miserable Monaco showing, with Rosberg seventh.

Brackley-based Brawn GP's Rubens Barrichello was eighth, with Mark Webber ninth in his Red Bull and Nelson Piquet tenth for Renault.

Felipe Massa, who has won this race for the last three years from pole, was down in 11th, followed by British pairing Button and Hamilton.