Murray is pushed to the limit as he battles through to semi-finals
Defending champion Andy Murray guaranteed that he will play for another Olympic medal after battling past Steve Johnson to reach the semi-finals.
Thursday's swirling wind, which contributed to Murray almost crashing out to Fabio Fognini, had died down and the World No.2 initially found the conditions more to his liking.
But, after a dominant opening set, he faltered in the second and again found himself in a real fight before recovering from a break down in the decider to win 6-0 4-6 7-6 (7-2).
Murray will now face fourth seed Kei Nishikori in the last four today, with Rafa Nadal meeting Juan Martin del Potro in the other semi-final clash.
The 29-year-old is very much the form man of world tennis having now won 27 of his last 28 matches, 16 in a row and 10 in succession at the Olympics.
Rain delayed the start of play for half an hour and Murray seemed keen to make up for lost time, breaking Johnson's serve and racing through the first set in just 26 minutes.
The second set was where it all went wrong for Murray against Fognini and Johnson ended the Scot's run of 12 straight games across the two matches with a break in the opening game.
The second seed missed his only break point and Johnson served out the set to love.
The American's response after his first-set mauling had been impressive and he made the first breakthrough in the seventh game of the decider with a Murray-esque lob.
The Scot could barely contain his frustration but his fighting spirit can never be questioned and he hit straight back before saving another break point.
Johnson twice served to stay in the match, forcing a deciding tie-break. But Murray secured the early mini-break and never let his advantage slip.
Meanwhile, Monica Puig will become the first female athlete from Puerto Rico to win an Olympic medal after beating Petra Kvitova 6-4 1-6 6-3 to reach the women's singles final.