Britain's Andy Murray recovered from a shocking start to beat German Rainer Schuettler 1-6 6-0 6-1 in the second round of the Qatar Open.
Murray will face Thomas Johansson in the quarter-finals in Qatar
Murray looked badly out of form as he was broken twice in the first set, failing to trouble Schuettler's serve.
But the Scot impressively forced his way back into the match and dominated the second set to take it to love.
Murray romped through the third set to seal victory and set up a quarter-final against Thomas Johansson on Thursday.
Johansson progressed with a routine 6-3 7-5 win over Germany's Michael Berrer, and the winner of his tie with Murray could well face top seed Nikolay Davydenko in the semis.
The Russian overcame Frenchman Fabrice Santoro, 6-3, 6-3 in his second round match and will now meet fellow countryman Dmitry Tursunov in the quarter-finals.
It was a Jekyll and Hyde performance from Murray, who went from the ridiculous to the sublime in Doha.
Schuettler made a flying start by holding to love and he was soon putting Murray in trouble on the 20-year-old's serve, with some fierce returns setting the tone for the first set.
The world number 11 clawed his way back into the game from 0-30, but Schuettler kept his cool to break and then held easily again to storm into a 3-0 lead.
Murray eventually got off the mark - though he was taken to deuce - before Schuettler served out to love and then, crucially, broke an out-of-sorts Scot again to move 5-1 ahead.
Schuettler yet again won his serve to love to wrap up an embarrassingly easy first set in just 29 minutes.
Murray desperately needed to sort his serve out and, despite being taken to 30-30 in the first game of the second set, he found enough rhythm to secure the early advantage.
The hold of serve gave Murray a much-needed lift, and a wide forehand from Schuettler in the next game handed the Scot his first break of the match.
Murray was suddenly in the ascendancy and he held to go 3-0 up before some typically assured returns gave him the second break of the set and a comfortable lead.
I made too many mistakes in the first set
An audacious backhand lob helped him hold again, this time to love, before two stunning returns from a tired-looking Schuettler serves enabled the Scot to close out the set 6-0.
By now the momentum was all with Murray and a sensational forehand down the line helped him hold at the start of the third set and he soon raced into a 3-0 lead again.
Schuettler ended a run of nine successive games for Murray by finally holding his serve and then he threatened to break back, the Scot finding two massive first serves to keep his opponent at bay.
The world number 99's chance was gone and Murray broke him to love before seeing out the match on his own serve.
Murray admitted that his victory had been more a case of perseverance than inspiration.
"I made too many mistakes in the first set," said Murray.
"The most important thing was to hang in there. I changed my style of play in the second and third sets. I was coming to the net more and using the slice shots."
There was worse news for Jamie Murray as he lost in the quarter-finals of the doubles with his partner Max Mirnyi.
The pair lost 6-4 7-5 to Wesley Moodie and Jeff Coetzee to exit the tournament in disappointing fashion.