Melbourne, Jan 28 (AP) Roger Federer was not going to go gently, of course, no matter how daunting the number of match points -- his opponent accumulated seven! -- no matter how achy his 38-year-old legs, no matter how slow his serves, no matter how off-target his groundstrokes.

Federer still plays for the love of these stages and circumstances. Still yearns for more trophies, too. Down to his very last gasp, time and again, against someone a decade younger, 100th-ranked Tennys Sandgren of the United States, Federer somehow pulled off a memorable comeback to reach the Australian Open semifinals for the 15th time.

Despite all sorts of signs he was not quite himself for much of the match, Federer beat the biceps-bearing, hard-hitting, court-covering Sandgren 6-3, 2-6, 2-6, 7-6 (8), 6-3 on Tuesday in a rollicking quarterfinal that appeared to be over long before it truly was.

"As the match went on, I started to feel better again and all the pressure went away," 20-time Grand Slam champion Federer said afterward.

"I don't deserve this one, but I'm standing here and I'm obviously very, very happy."

Federer was involved in a dispute with the chair umpire over cursing. Left the court for a medical timeout early in the third set, then was visited by a trainer later for a right leg massage.

And, above all, found himself in a tense tussle with Sandgren, a 28-year-old from Tennessee who's never been a major semifinalist and was trying to become the lowest-ranked man in the Australian Open's final four since Patrick McEnroe -- John's younger brother -- was No. 114 in 1991.

Oh, how close Sandgren came to the monumental upset.

After rolling through the second and third sets as Federer's serves dropped from an average of 112 mph to 105 mph and his unforced errors totaled 30, Sandgren led 5-4 in the fourth set. With Federer serving, Sandgren had a trio of opportunities to end things and complete a career-defining victory. On the first, Sandgren dumped a backhand into the net. On the second, he pushed a forehand wide. On the third, another forehand found the net.

On they went to a tiebreaker, which included the bizarre sight of a ballkid running into Sandgren's right calf at the 3-all changeover. Didn't seem to bother the guy, though, because he grabbed the next three points to put himself a single point from winning.

But Sandgren failed to close the deal at 6-3 ... or at 6-4 ... or at 6-5 ... or at 7-6.

"Got to get lucky sometimes, I'll tell you that," Federer said.

"Because in those seven match points, you're not under control." On Federer's own second chance to take that set and force a fifth, Sandgren hit a ball that landed near the baseline. Federer thought it might be out -- he turned to look at a line judge for a call that never came -- yet barely flicked it back in a defensive manner, and Sandgren's overhead smash went long.

Federer wagged his right index finger overhead -- the universal sign for "I'm No. 1!" -- and was on the right path. He ended the victory with a service winner at 119 mph, a little more than an hour after first staring down defeat. (AP)

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