Ferrari's Fernando Alonso set the opening pace this morning on the streets of the Principality as the Monaco Grand Prix weekend got underway in warm and sunny conditions. The Spaniard posted a time of 1m16.265s to end the ninety-minute session over three tenths clear of Lotus's Romain Grosjean.

The field didn't have the full ninety minutes at their disposal however, as a late-session red flag prematurely brought running to an end with nine minutes still left on the clock. Heikki Kovalainen's Renault engine let go as he accelerated from Portier, filling the tunnel with smoke and spewing oil on the track.

On the timesheets, Alonso's closest challenger Romain Grosjean lapped in a time of 1m16.630s, over a third of a second off the pace, with Sauber's Sergio Pérez bouncing back strongly from his high-speed shunt here last year to go third on a 1m16.711s. McLaren's Lewis Hamilton came fourth (1m16.747s), while Spanish Grand Prix winner and Monaco specialist Pastor Maldonado put his Williams in fifth place (1m16.760s).

Others finishing inside the top ten during the session were Ferrari's Felipe Massa (1m16.843s), Sauber's Kamui Kobayashi (1m17.038s), McLaren's Jenson Button (1m17.190s), Red Bull's Sebastian Vettel (1m17.222s) and Mercedes' Nico Rosberg (1m17.261s).

Force India and Toro Rosso ended the session with both their cars outside the top ten, while Bruno Senna finished only 17th on a 1m18.617s, almost two seconds shy of his team-mate. Caterham continued to lead the battle of the final three teams, with HRT's Narain Karthikeyan beating both Marussias and his own team-mate.

Kimi Räikkönen failed to complete a timed lap in his Lotus after requesting a complete change of his steering system. He completed only a single installation lap before remaining in the garage for the remainder of the session.