About a month after losing in the first round of a Grand Slam tournament for the first time in her career, Williams hit a tournament-record 24 aces Thursday to reach her seventh Wimbledon final.
"I honestly didn't feel great on my serve today. I really didn't," Williams said after beating Victoria Azarenka of Belarus 6-3, 7-6 (6) on Centre Court. "I thought my serve was off, and apparently clearly it wasn't, so maybe I should be off a little more."
Williams has won 13 Grand Slam titles, but her last one came at the All England Club two years ago. Shortly after that victory, Williams cut her feet on glass at a restaurant, leading to a series of health problems, including being hospitalized for clots in her lungs.
"I have so much appreciation for every moment on the court," Williams said. "I really take pride in playing, especially playing such big, amazing tournaments like this."
In Saturday's final, Williams will face Agnieszka Radwanska. The third-seeded Radwanska became the first Polish player to reach a Grand Slam final since 1939 by beating Angelique Kerber 6-3, 6-4 in the other semifinal.
"I'm just going to try to mix it up," said Radwanska, who cut short her post-match news conference because of a coughing fit. "Of course, every match is different, so I'll see after tomorrow how it's going to be."
On Friday in the men's semifinals, defending champion Novak Djokovic will face six-time winner Roger Federer, while Andy Murray will take on Jo-Wilfried Tsonga.
Williams and her big sister Venus have been ever-present at Wimbledon since the turn of the century, with one or both reaching the final in 11 of the past 13 tournaments. Between them, they have won nine titles at the All England Club.
On Thursday, the 30-year-old Williams looked more like the champion of yesteryear than the player who exited in the first round of the French Open five weeks ago.
She controlled play against Azarenka in the first set with her service game, winning 20 of the 24 points she started. She then went up an early break in the second set before Azarenka responded to make it 3-3.
They held the rest of the way, and Williams picked up her final three aces in the tiebreaker -- the last one on match point.
"I got a little tight in the second set. I couldn't relax," Williams said. "I was, like, looking too far in the future and she came back. But I'm glad I was able to get through."
The previous Wimbledon record of 23 aces was set by Williams in a three-set victory over Zheng Jie in the third round of this year's tournament.
"I don't see anybody else serving like this on the tour," Azarenka said. "I was just trying to get the ball back as many times as I could, but it wasn't enough today."
A few hours later, the Williams sisters reached the semifinals in doubles -- putting them two matches from their fifth Wimbledon title.
Earlier on Centre Court, Radwanska won with her steady play, winning five straight games to close out the first set after going down a break early.
She'll need more of that to have a chance against Williams in the final.
"She's been consistent this year, more consistent than I have," Williams said of Radwanska. "That already tells me from the beginning I really need to go out there and be ready to hit a lot of shots and be ready to play hard."
Radwanska can take over the No. 1 ranking if she beats Williams on Saturday. If not, Azarenka, who won the Australian Open, will take over the top spot from Maria Sharapova.
But just reaching a major final, the first of her career, is an achievement for both Radwanska and Poland.
The last Polish player to reach a major final was Jadwiga Jedrzejowska. But she lost in the final of the 1939 French Championships, two years after runner-up finishes at Wimbledon and the U.S. Championships.
"I'm just very happy that I can be the second one here in Wimbledon, being in the final. She lost in three sets that year," said Radwanska. "But I will try now and we will see."