The grid appeared to make a clean getaway initially, as all 20 cars made it through the opening lap without major incident having crept off the line.
Logan Sargeant had the first off-track excursion after a few laps as he locked up and slid into the barrier at turn six. He was able to reverse and keep himself in the race.
The two Haas cars ran in the points before Magnussen pitted onto intermediate tyres as the rain eased. Hulkenberg remained on wet tyres but began to lap three seconds slower than those on the green-walled tyres.
There was also a minor collision for Sergio Perez and Pierre Gasly, but the stewards ruled no further action was necessary.