Lewis Hamilton strengthened his grip on the Formula One world championship after controversially winning the Russian Grand Prix.

The Mercedes driver is 50 points clear of Ferrari's Sebastian Vettel with only five rounds remaining.

Here, Press Association Sport looks back at five things we learned from Sunday's race at the Sochi Autodrom.

1. Mercedes make the right decision

English teenager Lando Norris will head for the McLaren race team next season without adding the Formula Two championship to his CV. The feeder series, which has been won by Hamilton, Nico Rosberg and most recently, Charles Leclerc, instead appears to be heading in the direction of another English youngster, George Russell.

Norris, 18, endured a miserable weekend in Sochi, while Russell won the sprint race on another impressive weekend. He leads Alexander Albon – his only title contender – by 37 points with just the season finale in Abu Dhabi to come.

Whether Russell, the Mercedes junior driver, joins Norris on the F1 grid next year remains to be seen. Williams is his only option, but the struggling British team are yet to finalise their plans for 2019.