Heather Watson reached the second round of the Italian Open with a 6-4 3-6 6-0 win over world number 18 Sara Errani.
British number two Watson, who went through qualifying to reach the main draw in Rome, defeated the 2012 French Open finalist in two hours and 16 minutes.
Italian Errani needed two medical time-outs during the first set, which featured seven breaks of serve.
But she levelled at one set all before Watson powered away in the decider.
It means that Guernsey-born Watson, currently 55th in the world, will go through to face the Czech Republic's Barbora Strycova, ranked 36th, in round two.
And Watson admitted that the battle to qualify for a place at the Olympic Games in Rio is never far from her thoughts at the moment.
The top 56 players in the singles rankings are guaranteed qualification, with a few extra places likely to be available when the cut-off is made on 6 June.
"It was totally on my mind as we started that third set today," Watson told BBC Sport.
"It's just a big goal of mine and with it in the back of my mind it just motivates me and gives me that little bit extra.
"The Olympics is every four years, it's for your country. I can't even describe the atmosphere, it's unbelievable, and I just love being around the other athletes."
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