Serena Williams and Ana Ivanovic competed like it was the final of a Grand Slam event. Each gave everything they had, with Williams being the last one standing.
The world's No. 1-ranked player dug deep and pulled out a few winners, resulting in a trip to the semifinals of the Bank of the West Classic at Stanford's Taube Family Tennis Center.
Williams managed to bounce back from a first-set loss to beat Ivanovic, a former No. 1 player, 2-6, 6-3, 7-5, on Friday night.
Williams dropped three consecutive games in the third set to fall behind 4-3 and then ripped seven straight points to right the ship, pleasing the sellout crowd.
Ivanovic displayed her own resilience during the match. Williams was serving to go up 4-1 when the Serb rallied for the break. In the end, with 176 total points played, two points separated them, with Serena on the right side of the equation.
"She's not easy to play. She always gives 100 percent," Williams said. "I just kept fighting, stayed calm and focused on what I wanted to do."
Williams is assured of a 200th non-consecutive week at the top of the ladder while Ivanovic will return to the top 10 for first time in over five years.
"I think I can play loads better and that's good that I believe that," Williams said. "I thought we both played very well."
Ivanovic has won three titles this season, the first time she's won so many in a year since 2008. In her third appearance at Stanford, she reached the quarterfinal for the first time.
"It feels great to be back in the top 10," Ivanovic said. "I've worked so hard to get back. I've set high goals for myself and this was the first one."
Ivanovic took an injury timeout down 5-2 in the second set. She pinched a nerve in her left side when came down after a winning shot. It's the same thing that cropped up at the beginning of the year.
"It made it hard to move to the right but she was playing well at that time and using the angles," Ivanovic said. "Playing the No. 1 player in the world that close and having opportunities was encouraging."
Andrea Petkovic ended Venus Williams' run in the tournament, beating the former top-ranked player 6-1, 3-6, 7-5 in another quarterfinal Friday.
She gets a shot at Serena Williams on Saturday afternoon the televised (ESPN2) semifinal. The other semifinal will go off at 7 p.m. The winners will meet Sunday (2 p.m.) in the singles final, also televised live by ESPN2. The winner will earn $120,000, the highest payout in tourney history.
"You don't ever have the feeling you have something under control when you play either of them," Petkovic said. "They can hit so hard, and play consistently well. You always have to be on your toes."
Following a shaky start, 25th-ranked Venus Williams picked up her game in the second set and appeared poised to take over the match.
The 18th-ranked Petkovic rallied in the third set, taking leads of 3-1 and 5-3, to beat Williams in their first meeting since Luxembourg in 2012.
"I was not as on as I was on previous days," Williams said. "I had to fight through that and I think I almost did that. But she played the last two points better."
Petkovic, making her debut in the tournament, is looking for her third title of the season. She also reached the semifinal at the French Open.
"I played one of my best games in the third set at 5-5," Petkovic said. "Before that it was a weird match. There were so many momentum changes and so many ups and downs, I felt like I played four different matches in one."
The Serena-Ana match was similar as Ivanovic dominated the first set before Williams turned it around in the second set.
The third set took on a life of its' own. Both players simply refused to go away and battled through long rallies and silly errors.
Serena served for the match at 5-4 but Ivanovic denied her. Serena broke back and used a pair of aces to take a 40-0 lead before ending it when Ivanovic's return went just wide.
Varvara Lepchenko took care of qualifier Sachia Vickery, 6-1, 6-0, to earn her 400th career win, which includes all levels.
"It was hard to play someone from the United States who I know very well," Lepchenko said. "I've practiced with her often before. I knew this match would be mentally tough but was just trying to play the best tennis I could."
She will meet third-seeded Angelique Kerber in Saturday night's semifinal at 7 p.m. Kerber topped Garbine Muguruza, 6-2, 6-1.
"She is definitely one of the tougher lefty opponents out there, so I will have to play and fight for every single point," Lepchenko said. "I'm going to stay focused on my game and hopefully things will work out well for me."