Federer babysitting serve as he trucks on

After nearly being derailed in the opening round, the Federer Express has gained steam with each match at Wimbledon. Following his struggles early last week, Roger Federer opened the second week of the Championships in emphatic fashion, defeating juniors pal Jurgen Melzer 6-3, 6-2, 6-3 in the fourth round.

"It felt great," the six-time champ said after the match. "We knew each other 14 years and never played on tour, that's why I knew it could always be a very tricky match."

Ultimately, however, there was nothing tricky about it -- Federer established an early lead in each set and cruised through in less than an hour and a half.

Melzer did get back on serve after going down 3-0 to start the match, but the talented Austrian lefty usually found it difficult to keep up with Federer from the baseline.

"The start to the match was vital," Federer said. "Got the early break, he broke back, but I had already kind of found my range."

The only point of concern for the Swiss might be the way he came out serving, getting in only 42 percent of his first serves in the first set. What's more, he won three-quarters of the points on his second delivery and only two-thirds on his first -- unusual, because players go for more on their first serves and tend to have an easier time winning the points when those serves go in.

But Federer did turn the stats in his favor in the second and third sets, staying in the 90s on his first serve and creeping into the 60s on his second. That reflects his improved placement on the serve, which began to edge closer to the corners instead of crowding around the middle of the box.

"You look for your rhythm, try to make sure you get the right rhythm going," Federer said. "Maybe you start finding the T-serves [down the line], then you look for the wide serves."

His first-serve percentage was more erratic, however, improving to a desirable 67 percent in the second but dropping back to 52 percent in the third set. Given that low first-serve numbers contributed to Federer's problems during the first half of last year, when he was struggling with back problems, he'll want to keep babysitting this part of his game going forward.

Although he says he's fully fit at the moment, Federer did reveal that a thigh injury may have played a role during his defeat to Lleyton Hewitt in the final in Halle two weeks ago and his first-round scare against Alejandro Falla at Wimbledon.

"It was after my first-round match, my thigh was hurting a little bit -- which already was the case in Halle," he said. "But honestly, now I have no more problems."

The rest of the field may have been feeling a little more optimistic after watching the top seed go five sets in the first round and four sets against a qualifier in the second, but Federer made it clear he feels he's back on track after two days off and two straightforward wins against Arnaud Clement and now Melzer.

"I think my form is good now," he said. "Obviously the opposition is getting more and more difficult, but I think my game is following it up."