Roger Federer didn't have a Rafael Nadal problem on Thursday night at the Australian Open, he had a Roger Federer problem.

The 16-time Grand Slam champion was plagued by inconsistent groundstrokes, periods of malaise and a puzzling game plan in a 6-7 (5), 6-2, 7-6 (5), 6-4 loss to his longtime rival.

Nadal played spectacular tennis for the first two sets, losing a tight tiebreaker then dominating the second frame, before adopting a more defensive strategy that pressed Federer into making mistakes. The world No. 3 obliged.

Federer hit 63 unforced errors in the match, including a lazy overhead at the baseline that sailed wide on a break point opportunity in the final game. He had trouble putting away points that should have been his, then went for winners when he should have been content to let things play out. Early in the match he was fond of coming to the net and closing off one side of the court, leaving the rest wide open for Rafa to hit a passing shot. Its implementation was bizarre. Sticking with it when Nadal exposed its flaws was suicidal.

The loss was a devastating blow to Federer, who entered the showdown on a 24-match win streak. The last time he played Nadal at Rod Laver Arena, he lost a five-set heartbreaker. He shed tears after that match and pundits wondered whether the game had passed him by. Though he's 30 now, the same question won't be asked after this loss. Despite those lows, Federer hung around even when it felt like Nadal was pulling away.

The match's momentum shifts were dizzying. Federer was in vintage form in bursting out to a 3-0 lead. He quickly cooled before pulling out a first-set tiebreak. Nadal was in control of the second set and worked the 10-minute break for the Australia Day fireworks to his advantage, winning 11 straight points following the delay to take a 1-0, 40-0 lead in the third set. Federer held off those three break points and evened the match.

Even then, though, with the match still tied, Nadal felt in control. A moment later Federer broke Nadal and, just as quickly, Nadal broke him back. Back to even. In the third-set tiebreak, Rafa went up 6-1. Cruising. Then Roger got it back to 6-5 before dropping the set.

Back and forth it went in the fourth and final set. Losing the third figured to be the death knell for Federer, yet he earned three late break point opportunities, including one a 4-5 that he lost because of a freakish Nadal lob that somehow landed on the baseline. Federer had been expecting the shot to sail long. When it didn't, he hit a half-hearted overhead that sailed wide and evened the game at deuce. If Nadal's lob goes one inch farther, Federer extends the match again.

The reason Federer cried last time is because he was entering a tennis unknown. Then, he was the top player in the world who had just been bested on a different surface by the man who would dethrone him. Where would Roger Federer go from there?

This time, there is no great mystery about what happens to Fed. His path is clear. He'll continue contending in Grand Slams and will break through and win a couple when the draws and conditions allow. His off days, like Thursday, are still better than 95 percent of other players' good days. He is who he is, a great champion in winter. He's not going anywhere and isn't done winning Slams. As long as he stays consistence -- the man hasn't missed a Slam quarterfinal since May of 2004 -- he'll always be a contender. Another loss to Rafael Nadal doesn't change that.

Nadal will face the winner of the Novak Djokovic-Andy Murray match in Sunday's final.