"No way," was Serena's response when told of the numbers. "I was working so hard. I really wanted it."
And with that big serve, which produced 24 aces, one more than her own tournament record set in the third round, Williams Thursday defeated Victoria Azarenka, 6-3, 7-6 (6).
In tomorrow's final, Williams, a four-time champion, will face Agnieszka Radwanska, who with a 6-3, 6-4 win over Angela Kerber in the other semifinal became the first from Poland, woman or man, to reach a Grand Slam final in the Open era.
When tennis was strictly amateur, Jadwig Jedrzejowska of Poland was in the Wimbledon women's final in 1937 and the French Open final in 1939.
Although Radwanska is No. 3 in the rankings and could get to No. 1 by taking the Wimbledon championship -- if she doesn't, Azarenka will regain it -- Williams is the favorite to win for a fifth time.
"She's always tough," said Radwanska, who has won both their previous matches, including here in the 2008 quarterfinals. "Of course, she's playing great tennis on the grass."
In her six matches, Serena has 85 aces, and even when her forehand or backhand are erratic can rely on a shot John McEnroe, announcing for the BBC, called "The greatest serve I've ever seen in the women's game."
Venus, restricted by an anti-immune disease revealed during last summer's U.S. Open, was eliminated in the first round this Wimbledon. She continued in doubles with Serena -- they won again after Serena's win -- and as a spectator agonizing when it seemed Serena might lose the second-set tiebreaker. But with the score 6-6, Azarenka smacked a ball into the net and then watched helplessly as Serena's last serve became the last point.
"Victoria is a great player," Serena said. "She was playing so well, and I got a little tight in the second set. I was looking too far in the future. I was so close, but I can't do that. I was happy to get through that second set tie-break."
Serena has won 13 Grand Slams, but she is 30 in a sport ruled by 20-somethings. Her last Slam was 2010 at Wimbledon, after which she missed months because of a severely slashed foot from accidentally stepping on a broken glass, a pulmonary embolism and then a hematoma. "I almost died," she said more than once.
She was living large on Centre Court against Azarenka, who won the Australian Open in January but was a semifinal loser at Wimbledon for a second straight year. The roof was open and the sun, a rare sight in a summer of frequent rain, was shining down.