World number one Roger Federer was relieved to get through his first match at the Masters Cup in Shanghai on Sunday, when he beat Argentine David Nalbandian 6-3 2-6 6-4.
The defending champion, who has been out of action for seven weeks with a sprained ankle, made an uncharacteristically high number of unforced errors and found himself trailing 3-1 in the final set.
A backhand volley gave Federer the chance to claw his way back in the fifth game.
"Thank God I got out of that one, it would have made a big difference," the Swiss said. "I took the opportunity he gave me and I'm very happy right now.
"I haven't been in this situation very often in the last couple of years. It's always difficult to come out of it. I really hoped he would give me one opportunity and he did and I took it. It was a great relief."
Late qualifier Nalbandian said his unexpected call-up to the tournament meant that his preparations had been hurried.
"I feel I didn't prepare a hundred percent for this Masters. I was already on holiday when I received a last-minute call to come here," said Nalbandian.
"He (Federer) is a great, great player with a lot of confidence. When I took the break (in the third set) I knew it was a very important game and I tried to stay focused but it wasn't enough."
Nalbandian goes on to meet compatriot Guillermo Coria on Tuesday, while Federer will face Croatian number one Ivan Ljubicic.
