The Scot beat Juan Martin del Potro of Argentina to add to a wonderful day for Team GB
Andy Murray successfully defended his Olympic title after he beat Juan Martin del Potro to clinch the gold medal in the men's tennis.
The Wimbledon champion wept tears of joy after beating the Argentine in an epic four-set encounter lasting more then four hours.
Murray admitted the 7-5, 4-6, 6-2, 7-5 win - played in front of a raucous crowd dominated by Argentinian fans - had been "brutal".
"The match was very emotionally and physically draining so I feel a lot of relief and I'm tired but obviously very proud to have won another gold medal," he said after the match.
Murray's win came after Max Whitlock floored his rivals in the men's gymnastics by taking two gold medals in just 75 minutes apart.
The 23-year-old made history by becoming the first British man to win a gold medal in the floor gymnastics.
And shortly afterwards, he also took the top medal in the pommel horse final - days after he ended Great Britain's 108-year dry spell in the men's all-round gymnastics by picking up a bronze medal.
Whitlock helped Team GB to a haul of five golds in all - the team's most successful day ever at an overseas Olympics.
The medals sent Team GB soaring to second place in the medal table ahead of China.
Justin Rose became the first Olympic champion in golf for 112 years after he edged out Open champion Henrik Stenson, who secured the silver medal for Sweden.
The pair were tied as they teed up on the 18th hole, but Team GB's golfer finished 16 under par and two shots ahead of his rival partner - a dramatic end to the 72 holes of golf played in total.
Golf has not been an Olympic sport since the 1904 Games in St Louis, Missouri, yet more than 20 of the biggest names in the sport decided not to compete in Brazil - many citing concerns over the Zika virus.
Jason Kenny won Team GB's 14th gold of the Games when he beat his room-mate Callum Skinner to retain his Olympic cycling men's sprint title.
Kenny won the first two legs of the sprint final to dominate his team-mate, just as fellow Brit Chris Hoy had done to him in Beijing in 2008.
Elsewhere, Nick Dempsey was pipped to the post on a gold medal in the men's RS:X windsurfing final, but the Weymouth-born athlete managed to secure his second successive silver medal - a day after his 36th birthday.
After Team GB's successes, attention turned to the Olympic Stadium, where Usain Bolt won his third successive 100m gold and South African Wayde van Niekerk broke the 400m world record.
However there was disappointment for 2008 Olympic champion and Londoner Christine Ohuruogu, who missed out on the women's 400m final after finishing fifth in her semi-final.