Williams beats Wozniacki to reach Cincinnati final
Serena Williams celebrates during a match against Caroline Wozniacki of Denmark on day 8 of the Western & Southern Open at the Linder Family Tennis Center on August 16, 2014 in Cincinnati, Ohio - by Jonathan Moore
The world number one American, who claimed her 61st career WTA title at Stanford two weeks ago, will face off on Sunday against either fifth-seeded Maria Sharapova or ninth-seeded Ana Ivanovic.
Those two were meeting Saturday night in a battle of former world number ones.
Williams, playing a third tournament in a row for the first time since late 2007, improved her 2014 match record to 37-6.
The 32-year-old said that she needed a set to find her game after a slow start in a match which featured 15 breaks of serve, seven of them in the final set.
"I was feeling tired today, so in the second set I just told myself to hit big serves," said Williams, who followed up her win in Stanford by reaching the semi-finals last week at Montreal, where she lost to her sister Venus.
"I gave all that I had in me today," she said. "I didn't expect to do this well over the summer. I knew I needed matches so I entered three tournaments. But I'm still here."
Wozniacki came to the match after beating two top 10 players in a row -- Angelique Kerber and Agnieszka Radwanska -- for first time since the 2010 WTA Finals.
Wozniacki, who lost to Williams in three sets in the Montreal quarter-finals, won the opening set in half an hour despite double-faulting away a service game.
But Williams stepped up a gear in the second, helped to an early break by another of Wozniacki's double faults.
The third was a roller-coaster for both players, who are good friends off the court.
After five straight breaks of serve, Williams finally stopped as she held for a 4-2 lead.
She secured another break for 5-2 but then had to face a Wozniacki fightback, with the former number one reaching 4-5.
Williams finally closed it out in the next game after a game later after an hour and three-quarters. She finished with seven aces and benefitted from eight Wozniacki double faults.
"I knew I had to return better, and today I was able to do that," Williams said. "I actually felt better than in my other matches."
Russian superstar Sharapova, who leads Ivanovic 8-3 in their career series, was not expecting an easy time on court against the Serb.
"The tournament is still not done," the French Open champion said. "I certainly hope to raise my level and have a much better first set.
"It can't be any worse," she added in reference to her slow start against Simona Halep in the quarter-finals. "I'm just happy to be in that stage."