Andy Murray came from a set down to beat John Isner and reach the quarter-finals of the Shanghai Masters.
The British world number two, 28, showed excellent resilience in the face of the American's powerful serving to win 6-7 (4-7) 6-4 6-4.
Murray got the decisive break in the seventh game of the final set before serving out to seal victory after two hours and 31 minutes in China.
He will face Tomas Berdych or Gilles Simon in the last eight on Friday.
"It's always tough against him - you can feel like you have control when you are into rallies but it's tough to get into them sometimes," Murray told Sky Sports.