Andy Murray fought back from a set down to edge past John Isner and reach the Shanghai Rolex Masters quarter-finals.
The British number one dropped the first set on a tie-break before being run close by the 30-year-old American and holding on to record a 6-7 (4/7) 6-4 6-4 victory.
The 28-year-old took his record to 5-0 against his big-hitting opponent to set up a last-eight clash with the winner of the match between Gilles Simon and Tomas Berdych.
With the score level at 4-4 in the first set after Murray had won 91 per cent of service points, the Scot won the next game before the American again levelled.
The 2013 Wimbledon champion clinched the 11th game and broke his opponent in the next but could not see it out as Isner forced a tie-break.
The American got the edge over Murray following a great rally as he went 3-1 up in the tie break - with the Scot attempting a fightback to reduce the score to 5-4 down following an error - before Isner held on to take the first set 7-6.
Isner produced an unusual double-handed volley at the net to clinch a point on his way to taking the first game of the second set, much to the crowd's amusement.
Murray, who had won all four previous matches between the two, held serve to level despite getting frustrated with numerous errors on the way.
The next game went to deuce before the under-pressure Isner edged ahead and the world number two scraped level again despite a brilliant point from the American, who forced Murray to send the ball out from the net in an entertaining game.
Murray was unhappy with a decision at the end of the fifth game, calling Isner's shot short, and the Scot had words with the umpire as the games continued to go with serve until Murray broke his opponent in the ninth game and take a 5-4 lead.
The British number one served for the second set and clinched it after being held at break point to level the match and force a decider.
With both players showing signs of frustration, the first two games of the third set went with serve, a strong Murray forehand helping him clinch the second.
Murray took the next to deuce, sitting on break point twice before a great backhand from Isner helped keep the American on track as he went 2-1 up, while the next three games also went with serve.
Looking for his 36th title, the Scot dipped a looping shot over Isner as he broke in the seventh and the world number two went in front before his opponent slipped and fell to the deck on break point in the eighth as Murray's pressure paid off for a 5-3 lead.
Isner held serve in the ninth while Murray did enough in his next service game to wrap up the win as Isner's shot found the net.