Rafael Nadal of Spain celebrates after defeating Roger Federer of Switzerland during their semifinal at the Australian Open tennis championship, in Melbourne, Australia, Thursday.

MELBOURNE, Australia — Rafael Nadal beat Roger Federer 6-7 (5), 6-2, 7-6 (5), 6-4 in an Australian Open semifinal on Thursday night, the longtime rivals playing with the intensity they normally display when they meet in Grand Slam finals.

Though the stars who have met in eight Grand Slam finals were on the same side of the draw for the first time at a major since 2005, they played as if the title were at stake.

This time, though, only Nadal will have the opportunity to win another championship — on Sunday night when the Spanish left-hander plays the winner of Friday’s semifinal between defending champion Novak Djokovic and Andy Murray.

Earlier Thursday, Maria Sharapova overcame Petra Kvitova to advance to the women’s final against Victoria Azarenka. Sharapova broke Kvitova’s serve in the last game to finish off a 6-2, 3-6, 6-4 victory and the third-seeded Azarenka beat defending champion Kim Clijsters 6-4, 1-6, 6-3 to set up a Saturday night final at Rod Laver Arena that also will decide the No. 1 ranking.

Nadal, who holds a 6-2 edge in Grand Slam finals against Federer, made the key service break in the ninth game of the fourth set, making an incredible cross-court forehand winner from well behind the baseline, then watching as Federer hit a backhand wide to give Nadal a 5-4 lead.

Serving for the match, Nadal moved two points away from the win when Federer sent a backhand long. He won on his second match point when Federer floated forehand long.

At the end, Nadal smashed a ball up high in the stadium, almost clearing the roof. He then applauded along with the crowd when Federer walked off.

Two weeks ago, Nadal injured his right knee and wasn’t sure he’d be able to start the tournament. Now, he can barely believe he’s in the final.

“If you tell me that two Sundays ago, I really cannot imagine,” Nadal said. “For me, it’s a dream to be back in a final of the Australian Open.”

The 25-year-old Spaniard won the 2009 Australian title but lost in the quarterfinals in his next two trips to Melbourne Park. Federer hasn’t added to his record 16 Grand Slam titles since he won the 2010 Australian Open.

When the often enthralling play was suspended for 10 minutes late in the second set for an Australian Day fireworks display, Federer seemed to be affected most. Nadal led 5-2 at the time, and Federer lost his serve in the next game.