World number one Roger Federer survived a scare in his opening Olympics singles match against Colombia's Alejandro Falla before prevailing 6-3, 5-7, 6-3 on a packed Wimbledon Centre Court to book his place in the second round.
The 17-time Grand Slam winner and top seed, seeking his first singles gold medal, had three match points in the second set but then suddenly crumbled, hitting shot after shot into the net.
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The tense battle revived memories of the pair's first round clash at Wimbledon in 2010, when Federer recovered from two sets down to beat the gritty Colombian.
"I've struggled against him in the past at times," Federer told reporters after the match.
"All of a sudden I missed the match points, things got difficult and he played a great match to come back, so I'm relieved of course. Falla is a great player, counter-punches well, plays really well and made things really difficult for me."
Returning to Centre Court less than three weeks after winning his seventh Wimbledon title there, Federer made a solid start, breaking his opponent to secure the first set 6-3.
The second set began in a similar vein, and at 5-3 Federer looked on track to wrap up the win. But a string of errors saw Falla seize the opportunity to fight back, saving three match points and breaking the 30-year-old twice to take the set and force a decider.
Normal service appeared to be resumed on the sun-drenched court at the start of the third set, as the Swiss broke his opponent in the opening game. But the world number 51 swiftly broke back to level at 2-2.
Federer, who won doubles gold in Beijing with Stanislas Wawrinka, broke again to go 4-3 up, then held serve to force Falla to serve to stay in the match.
Buoyed by chants of "Let's go Roger, let's go", Federer didn't let the chance slip away from him this time, looking decidedly relieved to secure his victory.
In the next round, Federer will meet Julien Benneteau who he narrowly beat in the third round of Wimbledon this year after losing the first two sets to his French opponent.
Wimbledon women's champion Serena Williams had an easier time in her first round match against Serbia's Jelena Jankovic, with US first lady Michelle Obama cheering her on.
Obama watched from the players' box along with Williams's sister Venus as the fourth seed took just 61 minutes to see off former world number one Jankovic 6-3, 6-1.
Photograph: Clive Brunskill/Getty Images
