Roger Federer wipes his face on the practice courts at the All England Club. (Photo: AFP)
Here are three matches to look out for at Wimbledon on Tuesday, the second day of the Championships:
Roger Federer (SUI x3) v Lloyd Harris (RSA)
Head-to-head: First meeting
22-year-old Harris is ranked at a career-high 86 and will be making his Wimbledon debut after trying and failing to qualify in 2018. Harris, nicknamed 'The King' by his South Africa Davis Cup teammates, managed to win a match at a Grand Slam for the first time at the French Open this year, beating Lukas Rosol of the Czech Republic before losing to 15th-ranked Borna Coric in straight sets.
Against eight-time Wimbledon champion Federer, Harris will have his work cut out -- the great Swiss has not been beaten in the first round at the All England Club since 2002.
"The mindset has to be that you can play tough matches also the first week and still win in the second week," said Federer.
"If you can go through in straight sets or a comfortable four-setter, that's definitely always a good sign."
Rafael Nadal (ESP x2) v Yuichi Sugita (JPN)
Head-to-head: First meeting
Sugita is ranked at 274 in the world having been 36 just two years ago. The 30-year-old has not played a match on the main tour all year and needed to qualify to make the main draw at Wimbledon.
Despite his lowly ranking, Sugita has pedigree on grass courts having won the 2017 title at Antalya in Turkey before making the quarter-finals in Halle in 2018, beating top 10 player Dominic Thiem on the way.
Sugita has won just one match in his Wimbledon career when he defeated Britain's Bradley Klein in the first round in 2017 before losing a five-set second round clash against France's Adrian Mannarino.
"I won 2010 I think here after a very, very tough first couple of rounds," said Nadal.
"Going to be a tough one, a tough start against a player who already played three matches here. So it is a challenge."
Serena Williams (USA x11) v Giulia Gatto-Monticone (ITA)
Head-to-head: First meeting
Seven-time Wimbledon champion Williams will resume her pursuit of a 24th Grand Slam title against qualifier Gatto-Monticone of Italy, the world number 161.
The 31-year-old Italian is a late bloomer, having played her first professional match in 2002.
At the French Open in May she became the oldest Grand Slam debutante since 43-year-old Renee Richards at the 1977 US Open.
"I can't go into Grand Slams thinking about records. I just have to go in a Grand Slam and think about just the first match," Williams said.