Fernando Alonso made an early statement of intent for the eagerly awaited Monaco Grand Prix weekend, setting the fastest time of a curtailed first session of free practice.
Alonso clocked a quickest effort of 1:16.265 to finish the session ahead of Romain Grosjean and Sergio Perez. But the session was red flagged with eight minutes remaining after Heikki Kovalainen's Renault engine gave out in a plume of smoke in the tunnel, leaving a trail of oil on the racing line.
Lewis Hamilton was fourth quickest at the end of the session with Pastor Maldonado fifth as two of the favourites for the weekend showed early promise. The top five were separated by just half a second, but with drivers finding more and more time as their confidence grows there could have been further challenges to Alonso's time but for the early stoppage.
As soon as the clock had ticked over to 10am local time, cars flooded out onto a famous Monaco circuit bathed in sunshine, with only Jenson Button remaining in the pits. He finally ventured out 15 minutes into the session but complained of a lack of visibility as his team experimented with a new cockpit position in evaluating a higher chassis for next season. McLaren also opted to run a new front wing end plate, using a sensor to test loading on the front of the chassis.
With the track temperature reaching 28 degrees, Jean-Eric Vergne was the first driver to dial in competitive lap times, pushing hard enough to just avoid hitting the barrier on the final corner. As the big hitters began to get a feel for the circuit, so Vergne's spell at the top ended, first Romain Grosjean then Michael Schumacher bettering the mark.
Grosjean was strong throughout the session, but the same could not be said for his team-mate Kimi Raikkonen who failed to set a time after reporting problems with his steering after his installation lap.
While Alonso looked settled and controlled throughout each of his 22 laps, Felipe Massa was less so. Despite being quick and setting the sixth fastest time, Massa appeared to be slightly ragged and fighting the Ferrari much more than his team-mate.
The session saw its share of incident, Narain Karthikeyan out braking himself and disappearing down the escape road at Mirabeau, Mark Webber cutting the Nouvelle Chicane and Massa inexplicably kissing the armco approaching Tabac. Schumacher was also forced to return to the pit after a fault in his front wing saw it dragging along the circuit.