Fernando Alonso gave the Ferrari team an early morale boost by topping the opening free practice session ahead of this weekend's Monaco Grand Prix, but had the ominous presence of Red Bull's Sebastian Vettel looking over his shoulder as the chequered flag fell.

Alonso was the only driver to duck under the 1min 16secs barrier, but his 1min 15.927secs effort was only 0.073secs faster than Vettel managed, with yellow flags blighting the final minutes of the hour-and-a-half session and denying anyone else the chance to improve.

A succession of drivers took the opportunity to top the times, including Robert Kubica, Felipe Massa and, early on, Jaime Alguersuari, who virtually had the track to himself as the other teams opted for a slow start to the day. Kubica eventually ended the session in third spot, a further 0.016secs behind, with Mark Webber pipping Massa to fourth.

The remainder of the top ten was closely-matched, suggesting that a competitive Monaco GP could be on the cards come Sunday, with Toro Rosso's Sebastien Buemi the last man within a second of Alonso's pace. Michael Schumacher, McLaren duo Lewis Hamilton and Jenson Button and Force India's Adrian Sutil completed the leading group, with Schumacher's Mercedes' team-mate Nico Rosberg just outside, having spent over half the session in the pits as he had a suspected damper problem attended too.

The German was followed by Rubens Barrichello - seemingly on better form than he showed in the early stages of last weekend's Spanish GP - Tonio Liuzzi, Vitaly Petrov, Alguersuari and Nico Hulkenberg, the latter trio all getting their first taste of the Principality from the cockpit of an F1 car. Sauber's Pedro de la Rosa and Kamui Kobayashi were next up, already struggling before the Japanese rookie bounced his C29 off the chicane kerbing and into the seafront barriers, removing its front wing and damaging the left rear corner.

Kobayashi had already been off at Mirabeau earlier in the session, and accounted for two-thirds of the notable on-track incidents, with HRT's Karun Chandhok completing the set with a gentle spin into the barriers at Massenet. Unlike Barcelona, however, there was no recourse to the red flag and the session otherwise passed off without delay.

Chandhok, having completed just six laps on his Monaco F1 debut, unsurprisingly brought up the rear of the field, but was only fractionally slower than HRT team-mate Bruno Senna, while the rest of the new team cars lapped variably one and two seconds quicker, head on this occasion by Virgin's Timo Glock.