Formula 1 heads to the third race of the season with a genuine championship battle between Mercedes's Lewis Hamilton and Ferrari's Sebastian Vettel now shaping up.

The pair have each won a grand prix and finished second so far in 2017, with one analysis saying that the Ferrari is better in warmer conditions while the Mercedes prefers the cold.

"The cold helped us here," Hamilton admitted after winning in China.

However, his boss Toto Wolff insisted: "I don't see a pattern so far."

Hamilton continued after Shanghai: "It is very, very close.

"There were times when Sebastian put laps in and it was hard to match it. Then there were other times in the race when I was quicker.

"It's going to be one of the closest if not the closest fight I've experienced."

The season continues with the Bahrain Grand Prix this weekend.