Three-time Grand Slam finalist Andy Murray was made to struggle by a qualifier on Tuesday before surviving the opening round of the Dubai Open.
Murray, playing for the first time since almost halting Novak Djokovic in the semi-finals of last month's Australian Open in Melbourne, trailed 3-4 in the final set to Michael Berrer of Germany before coming through.
The third-seeded Scot admitted to being "frustrated" with his up-and down performance after sneaking through 6-3, 4-6, 6-4 against an increasingly ambitious world number 116.
Berrer became encouraged after Murray was unable to consolidate breaks of serve at 3-2 in the second set, and at 1-0 and 2-1 in the final set.
He became bolder and more aggressive, sometimes hitting fiercely angled drives, and more often charging the net to break up the rhythm of Murray's high quality ground strokes.
Murray played a well-controlled and canny last three games to escape from the increasing danger, and afterwards complained of having felt unwell.
"I felt like I wanted to vomit - I don't know if I wasn't hydrated," he said. "I was feeling really, really bad. I was getting it after long points and after getting up from the change-over.
"I wasn't drinking that much after the change-over in the third set and then I felt better."
Murray expects to give an account of his matches to his coach Ivan Lendl, the world number one on this date in 1983, who is at Delray Beach in the United States playing in the Champions Tour where he has reached the final.
"You can't look at your first match in four weeks and over-analyse," said Murray. But I shall need to be more solid in the second round."
There Murray will play Marco Chiudinelli, a Swiss qualifier who caused a minor upset by coming from 1-4 down in the final set to beat Nikolay Davydenko, the former world number four from Russia, by 6-4, 5-7, 6-4.
Another player seeded to reach the semi-finals here this week, Jo-Wilfried Tsonga, also had to battle hard to get over the first hurdle, beating a fellow former Australian Open finalist, Marcos Baghdatis 7-6(2), 6-4.
The world number five from France only arrived at midnight the evening before the match but twice recovered from 15-40 on his serve in the second set.
"I am confident about winning matches, and although I didn't play well today, I fought and won," said Tsonga, who next plays Lukas Rosol, the world number 96 from the Czech republic.
Another leading Frenchman, Richard Gasquet, was less fortunate. The former world number seven's tough run continued when he was forced to retire with flu against Mikhail Youzhny of Russia, which means Gasquet has not progressed past the quarter-finals of an ATP World Tour event since May.
He tried to soldier through the first round in the hope of recovering and playing better next time, but the draw landed him with one of the most difficult opening opponents of all.
Youzhny, the former world number eight, is also the man who won the final rubber against France in the 2002 Davis Cup final at Bercy, and is still playing at a very high standard.
After his fluent ground strokes had carried Youzhny to the first set 6-3 in exactly half an hour, Gasquet no longer had the energy to have any prospect of turning the match around and called it quits.