Mark Webber topped a rain-hit final practice session of 2013, ahead of what looks set to be a wet qualifying session for the Brazilian Grand Prix.

The Australian Red Bull driver, in his final Formula 1 race, posted a time of 1m27.891s late in the session, when conditions were slightly less treacherous.

Lotus’s Romain Grosjean was second quickest, ahead of team-mate Heikki Kovalainen. Valtteri Bottas was fourth quickest in the Williams, followed by Sauber’s Nico Hulkenberg.

World champion Sebastian Vettel finished down in 17th position, as the Ferraris, McLaren’s Jenson Button and Mercedes driver Nico Rosberg did not even set a time.

Sauber’s Esteban Gutierrez was the only driver to complete a full lap in the first 35 minutes of the session, as the rest of the field returned to the pits after installation rounds.

The rain intensified as the session progressed, and the action stopped completely for several minutes before some cars ventured out once more with some 25 minutes remaining. Vettel moved to the top of the times after his first timed lap, nearly 40 minutes into the session.

Gutierrez regained first place moments later, before Hamilton lowered the benchmark, becoming the first man to lap in the 1m29s as conditions improved thanks to all the running.

Webber was first to go out with the intermediate tires with 12 minutes to go, as teammate Vettel climbed out of his car and put an end to his morning. The Australian jumped to the top right away, going over 1.5 seconds quicker than Hamilton. Webber’s time meant all drivers put on intermediates for their final runs, but no one managed to beat his lap.

Despite the conditions, the session was mostly trouble-free except for a few offs that ended without consequence.

Pos Driver                Team                    Time       Gap      Laps 1. Mark Webber           Red Bull-Renault        1m27.891s            5 2. Romain Grosjean       Lotus-Renault           1m28.195s  +0.304s   5 3. Heikki Kovalainen     Lotus-Renault           1m28.595s  +0.704s   6 4. Valtteri Bottas       Williams-Renault        1m28.600s  +0.709s   12 5. Nico Hulkenberg       Sauber-Ferrari          1m28.830s  +0.939s   15 6. Jean-Eric Vergne      Toro Rosso-Ferrari      1m28.921s  +1.030s   5 7. Esteban Gutierrez     Sauber-Ferrari          1m29.215s  +1.324s   21 8. Pastor Maldonado      Williams-Renault        1m29.686s  +1.795s   10 9. Paul di Resta         Force India-Mercedes    1m29.736s  +1.845s   610. Adrian Sutil          Force India-Mercedes    1m29.913s  +2.022s   811. Lewis Hamilton        Mercedes                1m29.980s  +2.089s   812. Daniel Ricciardo      Toro Rosso-Ferrari      1m29.988s  +2.097s   913. Jules Bianchi         Marussia-Cosworth       1m30.635s  +2.744s   914. Charles Pic           Caterham-Renault        1m30.837s  +2.946s   1415. Max Chilton           Marussia-Cosworth       1m30.972s  +3.081s   1016. Giedo van der Garde   Caterham-Renault        1m31.154s  +3.263s   1417. Sebastian Vettel      Red Bull-Renault        1m31.$57s  +3.966s   418. Sergio Perez          McLaren-Mercedes        1m32.731s  +4.840s   419. Nico Rosberg          Mercedes                no time              420. Fernando Alonso       Ferrari                 no time              221. Jenson Button         McLaren-Mercedes        no time              122. Felipe Massa          Ferrari                 no time              2