CHARLESTON, S.C. (AP) -- It proved tough to be a top seed at the Family Circle Cup this week.
Jankovic fell to Bouchard 6-3, 4-6, 6-3 to start the round of eight before 17-year-old qualifier Belinda Bencic pulled off an even bigger shocker by eliminating Errani, a runner-up at the French Open in 2012.
Bencic, who had to win twice last weekend simply to make the field, took over in the final two sets for a 4-6, 6-2, 6-1 victory over the 26-year-old Italian. Bencic hadn't made it past the second round in two previous WTA events this year and wasn't expecting to advance to her first tour semifinals
''I was hoping for it and I was believing in me that it would come,'' she said. ''Yeah, I'm just really happy it came this week.''
Bencic is the first qualifier to advance this far at the Family Circle, an event where at least one of the top four seeds has reached the semifinals the previous 10 years. On Saturday, she'll face unseeded Slovakian Jana Cepelova, who pulled off a final surprise when she easily beat 12th-seeded countrywoman Daniela Hantuchova 6-2, 6-1.
Cepelova had defeated world No. 1 and two-time defending Family Circle champion Serena Williams on Tuesday night to start off a week of upsets.
Either Bencic or Cepelova will be the first unseeded player in the finals since 2011 when Elena Vesnina lost the championship to Caroline Wozniacki.
Errani looked confident and in control in the first set before getting overwhelmed by Bencic, who won 12 of the final 15 games. Errani talked to herself and even threw down her racket as Bencic's crisp shots clipped lines and moved out of reach.
Earlier, Bouchard rallied in the third set by winning five of the last six games to oust Jankovic, a past champion who came in ranked eighth in the world.
The 20-year-old Canadian reached the semifinals at a WTA tour event for the second time this season and fifth in her career.
On Saturday, she plays 14th-seeded Andrea Petkovic as she seeks her first title - something Bouchard thinks she's more than ready for.
''Every time I go into a tournament now and every match, I always believe I can win,'' she said.
Even when she falls behind, as happened in her past two matches. Bouchard trailed in the third set against Venus Williams on Thursday and Jankovic this time before rallying to victories.
''I feel confidence in myself,'' she said.
Petkovic topped ninth-seeded Lucie Safarova 6-3, 1-6, 6-1. The 26-year-old German, ranked 40th in the world, had struggled in recent events.
So Petkovic was pleased to shake off Safarova in the final set and advance to weekend play.
''I'm used to winning at least two, three matches and then losing to the top players, but it was a really tough few weeks for me in the past,'' she said. ''So now I'm just really, really happy and kind of relieved.''
Cepelova said the win over Serena Williams gave her a boost of energy she's carried throughout the work. ''Playing against Serena I really learned so much and every match gave me more confidence,'' she said.
Bouchard made it to the Australian Open semifinals this year, losing to eventual champion Li Na. In her only WTA final, she lost to Sam Stosur in Osaka in October.
Bouchard trailed 2-1 in the final set. She then dug in to win the next three games and take control. Her steady, strong groundstrokes wore down Jankovic.
''It was the third set and your concentration goes down a little bit if you're getting tired,'' Jankovic said. ''It was so close. It could have went either way, if I was a little bit tougher out there and played certain points a little smarter.''
The two also met in the quarterfinals last year, and Jankovic won 6-2, 6-1. Bouchard was ranked No. 114 then, but she's 20th now.
''Well, I didn't want it to be Groundhog Day today, for sure,'' Bouchard said. ''Same tournament, same round, same opponent.''
Not the same result.