NEW YORK, Aug. 28 (Xinhua) -- Third seed Roger Federer of Switzerland shook off a slow start against Damir Dzumhur from Bosnia and Herzegovina in their second-round clash of the US Open, clawing back from one set down to notch up a 3-6, 6-2, 6-3, 6-4 victory on Wednesday.

The Swiss, competing in his 100th US Open match, was made to work once again, having also dropped the opening set in his first-round clash on Monday against Indian qualifier Sumit Nagal.

"I have been in that position many times, starting not so well. I don't think there's a secret to a good start other than warming up well, being well-prepared mentally. Not underestimating your opponent. I did all of that. So when it happens like this back-to-back matches, it's just a bit frustrating more than anything, especially when the level is that low and there is that many errors and the energy is not kind of there," Federer said of his slow start.

The Swiss looked out of sorts in the early stages of the match, losing serve twice to fall 4-0 behind in the opening set. Dzumhur raised his level in crucial moments before winning the set at 6-3.

Federer finally came out in full flight to start the second set, pinning Dzumhur to the baseline with increased pace on both wings. The Swiss stormed to a 3-0 lead with an early break. After that, Federer never looked back.

"He was my idol. He was a person out of the court and on the court I was following. He was definitely, for me, the best player in tennis history," Dzumhur, who hadn't taken a set off Federer in their two previous meetings, said before his clash against Federer.

Next up for Federer is No. 25 seed Lucas Pouille of France or Daniel Evans of Britain. Federer is 2-0 against both men in their respective head-to-head records. Federer hasn't dropped a set to either player.