Petkovic holds off Bouchard, reaches Charleston final
Andrea Petkovic of Germany returns a shot on March 21, 2014 in Key Biscayne, Florida - by Matthew Stockman
Petkovic, seeded 14th and ranked 40th in the world, withstood the big baseline game of the rising Canadian star, who impressed with her run to the Australian Open semi-finals in January.
In fact, Bouchard controlled much of the match, needing just 29 minutes to lock up the first set.
She had three break chances in the sixth game of the second before Petkovic won the set to force the decisive third.
After a tight tussle, Petkovic finished it off in emphatic style, breaking Bouchard to love to seal the match.
It was an emotional win for the German, a former top-10 player who has battled a stream of injuries and almost fell out of the top 200 a year ago.
"I'm just very happy. I'm just very emotional right now," Petkovic said.
"The match was really tough. Genie played so well today -- she was so aggressive, and I have to admit I was a little lucky in the second set when I managed to turn the match around.
"It was just a few points here and there that made the difference."
Petkovic next faces either Slovakian Jana Cepelova -- the 20-year-old who stunned world number one Serena Williams in the second round-- or 17-year-old Swiss qualifier Belinda Bencic.
Bencic upset third-seeded Italian Sara Errani to reach the first WTA semi-final of her career.