Serena Williams celebrates as she holds up the trophy after winning the final of the Italian Open on Sunday

Serena Williams established herself as the favourite to retain her French Open title when she won her first trophy of 2016 at the Italian Open.

The world No 1 held off a strong challenge from compatriot Madison Keys to emerge victorious at the Foro Italico for the fourth time, winning 7-6, 6-3 in an hour and 24 minutes.

Beneath stormy skies Williams pulled off a much needed success, as she has played a sparing schedule this season and had yet to mount the podium this year.

 Her biggest problem this week turns out to have been the dog food she tried from some bizarre reason at her Roman hotel.

This was not vintage Williams, but if she can reproduce such form over two weeks at Roland Garros she will be the player to beat, for all that she has imploded in the finals of the last two Grand Slams.

Keys, 21, has been touted for several seasons as the next big thing in American women's tennis and this was the first time since 1970 that two players from the USA have contested the Italian final.

The world number 24 has a big ball strike not unlike Williams herself and swiftly went 2-0 up in somewhat windy conditions with the ever present threat of rain.

Williams levelled in the sixth game but it was close until the tiebreak, which also could have gone either way.

At 5-5 Williams's great experience showed and she reeled off two points in what turned out to be the decisive passage of the match. Keys is not the finished article as a competitor and then let it slip to 0-3 in the second, a position from which she could not recover despite breaking back at 2-5.

While there was a trace of nerves at the end Williams closed it out with a break and as she hugged her opponent at the net said, 'You're going to get to number one.'

Williams was understandably happy after her first title in nine months while Keys will be up to around 17 in the rankings on Monday.