Andy Murray received a rapturous welcome as he made a surprise appearance on Wimbledon's Centre Court, where rivals Roger Federer and Novak Djokovic cruised through to the next round.
The British tennis star, wearing a white tracksuit, stood out from guests as he was introduced to the crowd by BBC presenter Sue Barker.
Murray smiled and waved from the Royal Box - which has a strict dress code - alongside a host of Olympic and Paralympic gold medallists who were invited to watch the action.
As he enjoyed a lengthy applause from tennis fans, Barker said: "They love you, Andy."
But it was a brief appearance for the world number one, who then dashed off to the practice courts where he had been due at 1pm.
During the day's play, rival and seven-time Wimbledon champion Federer triumphed over German 27th seed Mischa Zverev, matching Djokovic in reaching the last 16 without having dropped a set.
Title favourite Federer was tested briefly late in the first set, but won the Centre Court match 7-6, 6-4, 6-4 in one hour and 49 minutes.
Beforehand, Djokovic came back from a break down to win the opening set before powering to victory against Latvian Ernests Gulbis.
The world number four won 6-4, 6-1, 7-6 to join players including Murray in the next round.
Elsewhere, a lively crowd cheered on British duo Marcus Willis and Jay Clarke as they triumphed in a tense five-set match on court three.
The pair beat all-French team and defending men's doubles champions Pierre-Hugues Herbert and Nicolas Mahut 3-6, 6-1, 7-6, 5-7, 6-3.
Home fans drowned out cries of "allez" from French supporters with raucous chants of "let's go GB, let's go" as the match reached its climax.
Willis and Clarke beamed as they enjoyed a standing ovation following their victory, as a delighted crowd shouted: "Let's all have a party with Willis and Clarke-y."
Guests from the world of sport are traditionally invited to watch play from the Royal Box on the middle Saturday of the tournament, and this year the All England Tennis Club honoured some of the stars from the Rio Olympics.
Murray became the first male tennis player to win two Olympic singles golds after triumphing at the 2012 and 2016 games.
Cycling's golden couple Jason and Laura Kenny, who are expecting their first child, were among the Team GB stars who took their seats in the Royal Box.
Mrs Kenny was joined by her Rio Olympic team mate Elinor Barker, while Mr Kenny had the chance to catch up with fellow men's team sprint medallists Callum Skinner and Philip Hindes.
Also invited were swimmer Adam Peaty, boxer Nicola Adams, rower Helen Glover and five of the gold medal-winning women's hockey team, as well as paralympians Libby Clegg and Georgina Hermitage.
Top seeds Jamie Murray and his Swiss partner Martina Hingis reached the third round of the mixed doubles, beating Britons Neal Skupski and Anna Smith 6-3, 6-0.
But the Broady sibling duo crashed out of the mixed doubles, losing to Czech team Roman Jebavy and Lucie Hradecka 6-4, 7-5.