CHARLESTON, S.C. - Montreal's Eugenie Bouchard, ranked 20, is through to the Family Circle Cup quarter-finals after a 7-6 (6), 2-6, 6-4 win over American Venus Williams, ranked 28th.

The match, which lasted two hours and 14 minutes in hot and windy conditions, saw Williams hit 39 winners and an equal number of unforced errors, while Bouchard went a slightly-less impressive 26-31.

Bouchard hit three aces, while Venus whacked twice that many. Bouchard double faulted four times, while Venus did the same seven times.

Bouchard, for the second straight match, feasted on second serves, winning 20 of 31 points on Williams’ second efforts, while Williams fared less well, winning just 21 or 39 second serves laid out by Bouchard.

Bouchard broke four times while being broken five times by the 33-year-old Williams, who had earlier survived a marathon match to reach the battle with Bouchard.

Bouchard, seeded sixth at the tournament, won in the second meeting on the WTA Tour between the players. Williams, a winner of seven Grand Slam titles, defeated Bouchard in three sets in Tokyo in 2013.

"In the second set she really started going for her shots. I just tried to keep fighting," Bouchard said in her on-court interview with ESPN's Pam Shriver. "It's always fun for me to play against such a great champion like Venus. She's still playing at such a high level and it was such a battle out there."

"She played a lot more consistently than I did," Williams said in her post-match presser. "I think my errors really hurt me a lot today, just a lot of up and down, a lot of errors. In the first set I kind of came from behind the whole set and then got into a position to win the set, and she was playing tough and staying in the points, and I started making the unforced errors again, which really didn't help."

Bouchard is slated to play sometime after 1 p.m. Friday against second-seeded Jelena Jankovic of Serbia, who beat the Croation Ajla Tomljanovic 7-5, 6-1 Thursday evening. 

Earlier, Sara Errani of Italy rallied to defeat Peng Shuai of China 7-6 (6), 7-6 (5) and advance to the quarter-finals.

The 11th-ranked Errani lost her previous three matches to Peng and appeared in trouble on Thursday after trailing 6-5 in each set. Errani squandered three match points in the second-set tiebreaker until she placed a drop shot that Peng could not track down to finish it.

Daniela Hantuchova of Slovakia won a third-round match over Teliana Pereira of Brazil in straight sets.

-With a file from The Associated Press