Three-time defending champion Novak Djokovic has been upset in a dramatic five-setter against Stan Wawrinka in the Australian Open quarterfinals, ending his 25-match winning streak at Melbourne Park. 

Wawrinka had lost 14 straight head-to-heads to Djokovic before Tuesday night's 2-6, 6-4, 6-2, 3-6, 9-7 win on Rod Laver Arena. 

Djokovic held off Wawrinka 12-10 in the fifth set in a 5-hour, 2-minute fourth-rounder here last year -- the longest Grand Slam match of the season -- and also edged him in five sets in the U.S. Open semifinals in September. 

This time, it was Wawrinka's turn. And he's into the semifinals at a major for just the second time. 

"Uh, last year I finished it was really tough but this year I came back it was a new year," he said. "I tried everything. He's an amazing champion. He never gives up. I'm really, really, really, really, really, really happy." 

This one took exactly four hours, and featured some stunning rallies. Both players were amazed at some of the shots coming back from the other side. The match even included a five-minute rain delay with Wawrinka serving at 5-5 in the fifth. 

Djokovic frequently held up and pinched his thumb and forefinger together to show how close the shots were to either hitting or missing the lines. 

Following after an early exchange of breaks in the fifth, Djokovic had to constantly serve to stay in the match and the pressure finally told. 

After all the superb shot making, it was a mis-hit from Wawrinka on a service return that set up match point. Djokovic chased it to the net but skewed his cross court drop shot too wide. He missed a volley on match point, his first defeat since the U.S. Open loss to Rafael Nadal and ending a 28-match winning streak. 

"He took his opportunities. He deserved his big win today," Djokovic said. "There's nothing I can say. I gave it my best, I gave it my all. It wasn't to be this time. 

"He showed his mental strength and he deserved to win. The only thing I can say is congratulations." 

Wawrinka will next play seventh-seeded Tomas Berdych, who also reached his first Australian Open semifinal when he beat No. 3-seeded David Ferrer 6-1, 6-4, 2-6, 6-4. 

On the women's side, 19-year-old Canadian Eugenie Bouchard reached the semifinals in her first trip to the Australian Open, beating Ana Ivanovic 7-5, 5-7, 6-2 to set up a showdown with two-time finalist Li Na. 

The result means two-time Australian Open finalist Li, who beat Flavia Pennetta 6-2, 6-2 in an earlier quarterfinal featuring two women who'll turn 32 next month, will have to face a teenager for the third time in the tournament. 

The 19-year-old Bouchard, the first Canadian to reach the Australian Open semifinals, played with composure against former No. 1-ranked Ivanovic, who started the season with a title at Auckland, New Zealand, and produced a major upset to eliminate top-ranked Serena Williams in the fourth round here. 

Bouchard went to the net 24 times and won 19 of those points. She broke Ivanovic's serve seven times, including the last game, and had to sit through a lengthy time out when she was trailing 4-3 in the second set while her opponent received treatment. 

The WTA Tour's "Newcomer of the Year" in 2013, Bouchard is playing just her fourth Grand Slam tournament, having lost in the second rounds at the French Open and U.S. Open last year and reached the third round at Wimbledon -- the only previous major where she'd managed back-to-back victories. The second of those was against Ivanovic, in straight sets -- their only previous meeting. 

Bouchard, who is from Montreal, has a growing group of supporters at Melbourne Park. After each match, fans have presented her with a different kind of stuffed, fluffy Australian animal -- she now has a kangaroo, a kookaburra and a wombat in her collection. 

Li is also a crowd favorite in Australia, where she lost the finals last year to Victoria Azarenka and in 2011 to Kim Clijsters and has reached the semifinals four times in the last five years. Azarenka, the two-time defending champion, is in the other half of the draw. 

Li won her only previous match against Bouchard in straight sets at Montreal in 2012. 

"We had a tough battle last time, and I think I didn't have a lot of experience back then," Bouchard said. This time I think I'll be ready." 

Li beat two 16-year-olds in the opening rounds and had to save a match point against Lucie Safarova in the third. Against No. 28 Pennetta, she was relentless, keeping the mistakes down while going for her winners. 

"After saving the match point, I think I got a lot of confidence," Li said of her close call in the third round. "Even more belief in myself." 

Li lost her serve just once -- while leading 5-0 in the opening set -- and finished off the 67-minute match with an easy forehand to the open court.