Red-hot Federer scorches del Potro

MELBOURNE, Australia -- For the second straight match at the Australian Open, Roger Federer crushed a dangerous challenger. And while young upstart Bernard Tomic probably didn't have a serious shot of taking down Federer, much more was expected from Juan Martin del Potro.

Federer, on a stifling hot day in Melbourne, eased past the Argentine 6-4, 6-3, 6-2 to reach the semifinals.

Tuesday's matinee promised much, given their classic encounter in the U.S. Open final in 2009, but Federer took control from the outset and piled a lot of pressure on del Potro, which he was unable to reciprocate.

Federer mixed up his backhand slice -- hitting it short and deep -- used the serve out wide effectively and didn't allow del Potro to get into a rhythm on the baseline. It's a game plan he's utilized so effectively against taller, more powerful foes.

"I'm really happy with my game," Federer said. "I'm moving well. I'm serving well. I'm hitting the ball clean. Today I thought, you know, in a very hot day with, you know, fast conditions, I was able to control the ball."

As good as Federer was, del Potro was equally disappointing.

Del Potro has lacked some belief since undergoing wrist surgery in May 2010.

Deja vu: Federer played his 1,000th match. In that stretch, how many times have we seen the 16-time Grand Slam champion win the toss, elect to serve, hold, then break his opponent? Federer did it once more to set the tone.

You can't do that, Juan: At this level, you can't give your opponent free points, especially if Federer is on the other side of the net. But del Potro did exactly that when he was broken in the fourth game of the second set. With Federer out of position, he struck a forehand volley wide. Then in a good spot to hit a backhand volley, del Potro let Federer's backhand pass sail past him, thinking it was going wide. It wasn't. A double fault capped off the catalogue of errors.

Not déjà vu: Federer was unusually vocal in the final game of the second set. Perhaps he was thinking of Flushing Meadows, where he led by a set but couldn't serve out the second at 5-4. It was the turning point, and del Potro triumphed in five. This time, at 5-3, Federer saved four break points. That was that.

"The second set, serving out the second set was key for me," Federer said. "You know, get through that tough patch, and then in the third it was a bit more free swinging for me."

Chair umps involved again: When Federer and del Potro played at the U.S. Open, it was an ill-tempered affair. Federer didn't like how long del Potro took to make a challenge and voiced his displeasure with Jake Garner. He'd go on to, conversing with Garner, utter the famous, "I don't give a sh-- what you say."

Del Potro became annoyed with Tuesday's chair umpire, Enric Molina, after Molina told him to speed things up between points. They had an extended conversation at the end of the first set.

In the second set, Federer queried Molina when he gave del Potro a point after the Argentinean successfully challenged a call.

We've seen umps make the wrong decision several times this tournament, but Molina was correct on both occasions.

Too polite: What was del Potro doing when he offered to replay the point that Molina gave to him following the challenge in question? "If it bothers you, we will replay [the point]," del Potro seemed to utter to Federer as they were both near the net. Federer declined.

Del Potro shouldn't have offered because he was right: Federer's backhand error came well after a linesperson called "out."

Serving notice: Federer served at only 57 percent but won 89 percent of those points. Del Potro served at 67 percent, but amassed only 57 percent of his first-serve points. Federer was also 15-for-20 at the net.

Hot dog: It wasn't as elegant as a Federer shot between the legs, but del Potro pulled off his own 'tweener at 0-3 in the first while chasing a lob. His reply was a pop up, and Federer put away the overhead.

Speaking of overheads: This fortnight has produced some shocking smashes: Federer, Serena Williams and Petra Kvitova have all flubbed the shot. Del Potro joined the club and erred at a crucial time. He missed a floater while facing a break point in the first, and Federer took a 2-0 lead.

Delpo's swoon: Since the start of 2010, del Potro is 0-6 against Federer, Nadal and Novak Djokovic. Yes, wrist surgery has hampered him, but del Potro needs a victory against the big three soon to give him a jolt of confidence.

London-based Ravi Ubha covers soccer and tennis for ESPN.com. You can follow him on Twitter.