Nico Rosberg tops final Monaco Grand Prix practice

The Spanish Grand Prix winner appeared to be involved in an incident with Sergio Perez's Sauber on the lap before at Portier and then lost control of his Williams on the entrance to Casino Square. He lost his left rear wheel as the car went out of control, before parking the FW34 at Mirabeau with three minutes of the session remaining.

An impressive Felipe Massa was second fastest ahead of a late-improving Sebastian Vettel and Fernando Alonso in the second Ferrari.

Unsurprisingly there was a little more urgency about getting on with the business of working through set-up programmes at the start of this session, and none was more in a hurry to get on with it than Kimi Raikkonen. The Finn did not even bother with an installation lap and was the first to record a time - that of 1m18.993s.

That mark did not last long at the top of the times as the two Mercedes joined him and Rosberg moved to the top, just six hundredths faster.

Force India's Paul di Resta had a brief moment in the sunshine just before quarter distance, but only until one of the stars of the weekend so far - Romain Grosjean - fired in a 1m16.812s.

The Frenchman, super confident in the switched on Lotus, worked that down to a 1m15.811s, and notably that remained the best time anyone did on the soft prime Pirelli tyre.

Just after half an hour Rosberg moved the mark forward with a super soft option lap of 1m15.751s. The Chinese Grand Prix winner then backed off for a lap before going even faster - the result a 1m15.159s. That would be enough to settle the argument.

Behind him Massa - looking much more secure in the cockpit of his Ferrari than of late - Alonso and Grosjean all also improved on the red-walled Pirellis.

It was only in the last 10 minutes that Vettel, who had a sideways moment on the exit of the Swimming Pool on a previous lap, finally moved into third place in a Red Bull that does not look easy to use on the Monaco streets.

Behind this quintet, Jenson Button's best super soft effort could only net him sixth fastest ahead of his McLaren team-mate Lewis Hamilton, Michael Schumacher, Perez (whose best lap was baulked by Nico Hulkenberg) and Mark Webber, who completed the top 10.

Raikkonen spent the session focusing on race set-up and was 12th quickest.

Maldonado's was not the only late session incident. Di Resta, who ended up 18th fastest, crashed into the barriers under braking for the chicane as the car snapped left over the bumps, but he was able to return to the pits under his own power with significant nose and front wing damage.

As for the Venezuelan, it remains to be seen whether he will be called to discuss his Perez incident with driver steward Nigel Mansell, which could cost him dearly on a track that is all about grid position.

Pos  Driver              Team/Car              Time       Gap       Laps
 1.  Nico Rosberg        Mercedes              1m15.159s            25
 2.  Felipe Massa        Ferrari               1m15.197s  + 0.038s  21
 3.  Sebastian Vettel    Red Bull-Renault      1m15.209s  + 0.050s  20
 4.  Fernando Alonso     Ferrari               1m15.210s  + 0.051s  20
 5.  Romain Grosjean     Lotus-Renault         1m15.445s  + 0.286s  18
 6.  Jenson Button       McLaren-Mercedes      1m15.471s  + 0.312s  19
 7.  Lewis Hamilton      McLaren-Mercedes      1m15.734s  + 0.575s  19
 8.  Michael Schumacher  Mercedes              1m15.893s  + 0.734s  23
 9.  Sergio Perez        Sauber-Ferrari        1m16.110s  + 0.951s  14
10.  Mark Webber         Red Bull-Renault      1m16.219s  + 1.060s  19
11.  Jean-Eric Vergne    Toro Rosso-Ferrari    1m16.226s  + 1.067s  20
12.  Kimi Raikkonen      Lotus-Renault         1m16.301s  + 1.142s  21
13.  Kamui Kobayashi     Sauber-Ferrari        1m16.311s  + 1.152s  19
14.  Daniel Ricciardo    Toro Rosso-Ferrari    1m16.479s  + 1.320s  20
15.  Nico Hulkenberg     Force India-Mercedes  1m17.027s  + 1.868s  20
16.  Bruno Senna         Williams-Renault      1m17.055s  + 1.896s  26
17.  Heikki Kovalainen   Caterham-Renault      1m17.276s  + 2.117s  25
18.  Paul di Resta       Force India-Mercedes  1m17.390s  + 2.231s  19
19.  Vitaly Petrov       Caterham-Renault      1m17.404s  + 2.245s  22
20.  Timo Glock          Marussia-Cosworth     1m18.259s  + 3.100s  18
21.  Pastor Maldonado    Williams-Renault      1m18.488s  + 3.329s  22
22.  Charles Pic         Marussia-Cosworth     1m19.099s  + 3.940s  17
23.  Narain Karthikeyan  HRT-Cosworth          1m19.147s  + 3.988s  19
24.  Pedro de la Rosa    HRT-Cosworth          1m19.151s  + 3.992s  19

All timing unofficial