Reigning Formula 1 world champion Lewis Hamilton has topped the timesheet for the second time today in a rain-affected practice session ahead of Sunday's Monaco Grand Prix.

Hamilton recorded the fastest time in the first practice, while his Mercedes teammate Nico Rosberg finished ninth fastest.

This time, Rosberg had a better run-out by finishing second in the standings, while Ferrari duo Sebastian Vettel and Kimi Raikkonen clocked the third and fourth quickest times respectively.

Midway through the session, the red flag was waved when Roberto Merhi slid down the chicane in his Manor and smashed into the barrier, causing the front of his car to hit the wall.

There was a lull in activity on the track as the rain began to fall and the majority of the drivers opted to sit out until the weather settled.

With around 10 minutes of the session remaining, Fernando Alonso returned in his McLaren, while some other competitors followed.

Full standings:

1. Lewis Hamilton (Mercedes)
2. Nico Rosberg (Mercedes)
3. Sebastian Vettel (Ferrari)
4. Kimi Raikkonen (Ferrari)
5. Daniil Kvyat (Red Bull)
6. Carlos Sainz (Toro Rosso)
7. Max Verstappen (Toro Rosso)
8. Fernando Alonso (McLaren)
9. Nico Hulkenberg (Force India)
10. Romain Grosjean (Lotus)
11. Sergio Perez (Force India)
12. Felipe Massa (Williams)
13. Valtteri Bottas (Williams)
14. Pastor Maldonado (Lotus)
15. Jenson Button (McLaren)
16. Daniel Ricciardo (Red Bull)
17. Felipe Nasr (Sauber)
18. Roberto Merhi (Manor)
19. Will Stevens (Manor)
20. Marcus Ericsson (Sauber)