Fernando Alonso tops first Monaco GP practice

Sauber driver Sergio Perez, returning to the scene of his frightening accident last year, was an impressive third fastest ahead of Lewis Hamilton, Spanish Grand Prix winner Pastor Maldonado and Felipe Massa.

There was the customary slow start to the session as teams were cautious of wasting tyres on the 'green' street track, leaving Jean Eric-Vergne and Toro Rosso team-mate Daniel Ricciardo with the track mostly to themselves.

Vergne worked down to a 1m19.066s before some of the bigger names began to hit the track on the 40-minute mark. Those included Michael Schumacher's Mercedes and Romain Grosjean's Lotus.

It was the Frenchman who would leave a lasting impression on the times as he first recorded a 1m17.645s to go quickest for the next 20 minutes until he was outdone by Alonso who lapped in a 1m17.126s - just as his team-mate Massa scraped the barriers at Tabac.

The Ferrari ace's time stood for all of four minutes as the session passed through the hour mark and then Grosjean responded again with a 1m16.751s.

This time it was Hamilton who bumped the Frenchman, putting McLaren top, going four thousandths quicker as the circuit began to get busy.

Once again Grosjean had an answer as he lapped in 1m16.630s only for Alonso to re-emerge from the pits with 15 minutes to go and fire in two super-quick laps, the first a 1m16.4s and the second an impressive 1m16.265s. That would prove enough.

The double world champion had set an even faster first sector (19.8) as the session entered the final 10 minutes when Heikki Kovalainen's Renault engine failed through the tunnel stopping the session, the Caterham grinding to a halt on the exit and extinguishing all visibility from the area. The resultant oil on the track meant the session could not be restarted.

Behind the top six, Kamui Kobayashi was seventh for Sauber, ahead of Jenson Button's McLaren, world champion Sebastian Vettel and Nico Rosberg.

Five-time Monaco winner Schumacher ended up 11th after damaging his front wing when he clattered the kerbs at the Swimming Pool, while 2010 winner Mark Webber was 13th in the second Red Bull.

Kimi Raikkonen completed just a single installation lap before deciding the Monaco-specific steering wasn't to his liking and decided to have it changed, wiping out the rest of his session.

Pos  Driver                Team                  Time                Laps
 1.  Fernando Alonso       Ferrari               1m16.265s            22
 2.  Romain Grosjean       Lotus-Renault         1m16.630s  + 0.365   17
 3.  Sergio Perez          Sauber-Ferrari        1m16.711s  + 0.446   19
 4.  Lewis Hamilton        McLaren-Mercedes      1m16.747s  + 0.482   12
 5.  Pastor Maldonado      Williams-Renault      1m16.760s  + 0.495   20
 6.  Felipe Massa          Ferrari               1m16.843s  + 0.578   19
 7.  Kamui Kobayashi       Sauber-Ferrari        1m17.038s  + 0.773   21
 8.  Jenson Button         McLaren-Mercedes      1m17.190s  + 0.925   13
 9.  Sebastian Vettel      Red Bull-Renault      1m17.222s  + 0.957   14
10.  Nico Rosberg          Mercedes              1m17.261s  + 0.996   18
11.  Michael Schumacher    Mercedes              1m17.413s  + 1.148   14
12.  Nico Hulkenberg       Force India-Mercedes  1m17.631s  + 1.366   18
13.  Mark Webber           Red Bull-Renault      1m18.106s  + 1.841   14
14.  Jean-Eric Vergne      Toro Rosso-Ferrari    1m18.209s  + 1.944   25
15.  Daniel Ricciardo      Toro Rosso-Ferrari    1m18.252s  + 1.987   28
16.  Paul di Resta         Force India-Mercedes  1m18.302s  + 2.037   16
17.  Bruno Senna           Williams-Renault      1m18.617s  + 2.352   20
18.  Heikki Kovalainen     Caterham-Renault      1m19.039s  + 2.774   20
19.  Vitaly Petrov         Caterham-Renault      1m19.341s  + 3.076   16
20.  Narain Karthikeyan    HRT-Cosworth          1m20.838s  + 4.573   26
21.  Charles Pic           Marussia-Cosworth     1m20.895s  + 4.630   18
22.  Timo Glock            Marussia-Cosworth     1m21.638s  + 5.373    9
23.  Pedro de la Rosa      HRT-Cosworth          1m22.423s  + 6.158   15
24.  Kimi Raikkonen        Lotus-Renault                               1

All Timing Unofficial