Boom Canadian teenager Eugenie Bouchard has upset Serbia’s Ana Ivanovic to advance to the semi-finals of the Australian Open.

With Ivanovic twice requiring medical treatment on her right thigh late in the second set, Bouchard seized her opportunity, going on to win 5-7 7-5 6-2 in a match lasting two hours and 24 minutes.

Her reward is a semi against China’s No.4 seed Li Na, who hammered Flavia Pennetta from Italy 6-2 6-2 earlier on Wednesday.

The 30th-seeded Bouchard won the junior Wimbledon title in 2012, but did not make her senior grand slam debut until last year’s French Open.

Ivanovic, the No.14 seed, had caused the biggest upset of the Australian Open back in the fourth round when she downed world No.1 Serena Williams.

China’s Li advanced to the last four for the fourth time in the past five years with a 6-2 6-2 demolition of Pennetta.

In a match between two 31-year-olds, Li needed only 67 minutes to end Pennetta’s best Open campaign and advance to a semi-final showdown with Bouchard.

Although Li claimed her only major title to date three years ago at the French Open, it is at Melbourne Park where she has performed most consistently at grand slam level.

She lost the 2011 and 2013 finals to Kim Clijsters and Victoria Azarenka respectively and also reached the Australian Open semis in 2010.

“I always look forward to coming back to Melbourne,” said Li.

“I hope I can do one more step this year.”

The Chinese player has dropped only four games in her most recent two matches against Ekaterina Makarova and Pennetta after coming back from match point down to squeeze past Czech Lucie Safarova in the third round.

“Of course I got a lot of confidence from that,” said Li.

“Finally I came back to win that match.”

Li dominated the outright winners’ count 23-14 against Pennetta and also committed 10 less unforced errors than her outgunned Italian opponent.