Stanislas Wawrinka has beaten Andy Murray in straight sets 7-6(4) 6-4 to advance to the last four of the ATP World Tour Finals in London.
Both players produced solid tennis in the first set and were able to fend off break points to send the set into a tie-breaker.
Murray raced into a 4-2 lead as he capitalised on errors from the Swiss, but the number two seed made two errors of his own to bring Wawrinka back into the game.
The number four seed proved to be clinical to close out the set to claim the tie-breaker 7-4 following a loose lob shot from Murray.
Wawrinka seized on a lack of concentration from Murray at the start of the second to clinch an early break point to increase the pressure on the Scot.
The 28-year-old pressed to get back into the match, but the Swiss held his composure on serve to take the match away from Murray.
Further mistakes from the Scot handed another break point to Wawrinka and once again he proved to be clinical as Murray could only send a forehand into the net, which allowed the Swiss the chance to serve out the match.
However, Murray was given hope when he managed to break back before securing a vital hold to extend the match, but the Scot could not take two further break points as Wawrinka battled off his challenge to reach the last four.
Wawrinka will face Roger Federer in the semi-finals of the tournament.