Russian Grand Prix: Nico Hulkenberg tops delayed practice

Force India's Nico Hulkenberg pipped Mercedes' Nico Rosberg to fastest time in a Russian Grand Prix first practice disrupted by diesel on the track.

Hulkenberg was 0.052 seconds quicker than Rosberg as world champion Lewis Hamilton spun at the penultimate corner on what could have been a faster lap.

The track speeded up throughout the session, which started half an hour late for the most bizarre of reasons.

A cleaning truck dropped a large amount of diesel overnight to cause the delay.

The spillage drenched the track at Turns Seven and Eight, and even when the session got under way that section was extremely slippery, leading several drivers to spin or run wide.

Track marshals frantically try to sweep diesel and water off the Sochi circuit

"What a mess," Ferrari driver Sebastian Vettel said as he drove through the section on his first lap.

McLaren's Fernando Alonso, taking part in his 250th grand prix weekend, entertained viewers with some spectacular laps early on while most preferred to stay in the garages.

Once the teams started to run with about 15 minutes to go, times began to tumble, and inevitably it was the last car across the line that set the fastest time.

Vettel was third fastest in the end, ahead of Force India's Sergio Perez and Red Bull's Daniel Ricciardo.

Hamilton ended up seventh fastest, behind Toro Rosso's Carlos Sainz, following his spin on his final lap.

Rosberg spent the first part of the session practising starts, aware that he has lost out to Hamilton at the start of virtually every race since new procedures restricting driver aids were introduced five races ago.

He was also aware that he needs to beat his team-mate this weekend to have any chance of closing him down in the championship, where Hamilton leads Rosberg by 48 points.

Rain is predicted for the second session, which is live on the Red Button from 11:55 BST.

Russian GP practice results

Russian GP coverage details