Nico Rosberg set the fastest time of opening practice for the Chinese Grand Prix, in a session that was red-flagged for a long period due to a number of unrelated tyre issues.

The tyre problems began early in the session when the left-rear of Felipe Massa’s Williams began to come apart as he went about his first run. The tyre was eventually shed as he went into Turn 6 and the Brazilian was pitched into a spin. He managed to make it back to the pits but with debris scattered across the track, the red flags briefly appeared.

After a spell in his team’s garage Massa reappeared with about half an hour left on the clock in the session. However, he soon suffered another left rear failure, the tyre apparently being damaged by contact with a body part on his car.

Massa was followed, on track and into trouble, by Renault’s Kevin Magnussen.

The Dane suffered a suspension failure on the same back straight and he too limped back to the pits, where because both cars had been running soft tyres a Pirelli investigation immediately began.

At this point the red flags came out and there a long delay as more debris was cleared from the track and the tyre checks continued. Pirelli later confirmed that none of the failures was caused by a tyre issue.

With seven minutes left on the clock, Rosberg, who had been second fastest behind team-mate Lewis Hamilton before the stoppage, emerged for a run on the soft tyres.

He was joined by Hamilton but it was the German who made the most of the compound, setting a time of 1:38.037 to take top spot ahead of the Briton.

Hamilton was left with P2,  just over a tenth adrift of the championship leader. Sebastian Vettel was third fastest, though the Ferrari driver was half a second behind Hamilton on the same soft tyres.

Rosberg, though, wasn’t immune to problems and as the session drew to a close, he was forced to make his way slowly back to the team’s garage in ‘limp home’ mode due to a suspected power unit issue.

Daniel Ricciardo was fourth fastest, just over a second behind Rosberg, with the Australian also setting his best time on soft tyres. Ferrari’s Kimi Raikkonen finished fifth ahead of Daniil Kvyat in the second Red Bull, Toro Rosso’s Carlos Sainz Jr, the McLaren of Jenson Button, Force India’s Nico Hulkenberg, and the second Toro Rosso of Max Verstappen.

2016 Chinese Grand Prix – Free Practice 1
1 Nico Rosberg Mercedes 1:38.037 16
2 Lewis Hamilton Mercedes 1:38.183 16
3 Sebastian Vettel Ferrari 1:38.665 12
4 Daniel Ricciardo Red Bull 1:39.061 13
5 Kimi Raikkonen Ferrari 1:39.155 11
6 Daniil Kvyat Red Bull 1:39.625 14
7 Carlos Sainz Toro Rosso 1:39.676 12
8 Jenson Button McLaren 1:39.974 11
9 Nico Hulkenberg Force India 1:40.169 13
10 Max Verstappen Toro Rosso 1:40.232 13
11 Sergio Perez Force India 1:40.347 15
12 Fernando Alonso McLaren 1:40.538 11
13 Valtteri Bottas Williams 1:40.828 10
14 Romain Grosjean Haas 1:41.358 9
15 Marcus Ericsson Sauber 1:41.393 18
16 Rio Haryanto Manor 1:41.614 20
17 Jolyon Palmer Renault 1:41.816 16
18 Pascal Wehrlein Manor 1:42.908 14
19 Felipe Nasr Sauber 1:42.980 8
20 Kevin Magnussen Renault  6
21 Esteban Gutierrez Haas  2
22 Felipe Massa Williams  4