Roger Federer will be looking for payback when he opens the defence of his ATP Indian Wells title with a second round match against Argentina's Federico Delbonis on Saturday.
There are not many players who can say they have a winning record over 20-time grand slam winner Federer but Delbonis is one of them.
In their only other ATP meeting in 2013, Delbonis won on clay in Hamburg 7-6, 7-6.
Delbonis, who is ranked 67th in the world, is no stranger to upsets in Indian Wells. In 2016 he shocked world No 2 Andy Murray to reach the fourth round.
He reached the second round here this week by saving two match points to defeat another American Ryan Harrison in three sets.
Federer, who regained the world No 1 ranking last month, is on a quest to make history in the California desert by winning an unprecedented sixth Indian Wells title. The 36-year-old Swiss marvel continues to defy the ageing process, claiming his 20th grand slam title and sixth Australian Open crown in January.
He has enjoyed a perfect start to 2018 by winning both events he has competed in and taking his career singles title tally to 97. Federer said on Thursday that he won't be taking anyone for granted in this draw.
"I didn't come here to lose in the first round two and two," he said. "I care about the moment. I care about the results."
Elsewhere, unseeded Gael Monfils rolled to an easy 6-3, 6-3 victory over Aussie Matthew Ebden in his opening match at the ATP Indian Wells tournament on Friday. The 31-year-old Frenchman needed just 71 minutes to dispatch Ebden.
Monfils began 2018 by claiming his seventh career ATP Title in Doha, but this is the first time he has come into Indian Wells unseeded in the men's draw since 2008.
Monfils hammered six aces, won 68 per cent of his first serve points and broke Ebden four times. Monfils improved to 2-0 lifetime over Ebden having beaten him previously at the 2010 Australian Open.
Monfils will face world No 18 John Isner in the second round. The Frenchman has beaten Isner five times in nine career meetings, including winning four of their past five. Their most recent encounter took place a year ago in the California desert, with Monfils winning easily 6-2, 6-4 to reach the third round.
Indian Wells marks the first time playing on hard courts for Monfils since the Australian Open in January. He is coming off four straight weeks on the South American clay court circuit so needed to make the necessary adjustments.
"The ball was flying quite a lot. It was not easy to adapt but today I was just lucky to get the win and in straight sets is always good. I will be focused for the next one," Monfils said.
Ebden committed five double faults and won just 39 per cent of his second serve points on Friday. He is playing in the Indian Wells main draw for the first time since 2014.
Wild card Ernesto Escobedo surprised fellow young gun Frances Tiafoe 7-5, 6-3 in the first career meeting between the two Americans.
Tiafoe, 20, who is ranked 64th in the world, was fresh off his first career title at Delray Beach on February 25.
Escobedo, 21, is making his Indian Wells debut.
In other men's matches on Friday, Felix Auger-Aliassime, who is the youngest player in the draw at 18 years, seven months, defeated Vasek Pospisil 6-2, 7-6 in an all-Canadian second round match-up.
Portugal's Joao Sousa rallied to beat Mikhail Youzhny of Russia, 4-6, 6-4, 7-6.