Serena Williams wants to go out with a bang.


With the U.S. Open semifinals and finals looming Friday and Saturday, Williams wants to add yet another major championship — the 15th of her career — to her trophy case.


"Just go out with a bang," said Williams, a three-time U.S. Open champ who last won here in 2008. "Just do the best that I can. That's what I want to do."


In Friday's semis, No. 4 Williams faces No. 10 Sara Errani of Italy in one match, while No. 1 Victoria Azarenka meets No. 3 Maria Sharapova in the other.


The final is set for primetime Saturday night on CBS.


Twice in the last three years, Serena has been undone by her own temper when she exploded at Open officials at critical times late in the tournament.

If she can avoid a similar meltdown and keep serving at such a blistering pace, she will be tough to beat.

Williams, who many feel has the best serve in the history of the women's game, leads the women's draw with 41 aces and is tied for the fastest serve at 124 mph.

"She was serving unbelievable," former world No. 1 Ana Ivanovic said after Williams beat her, 6-1, 6-3, in 58 minutes in the quarterfinals. "She was hardly missing serves. That puts a lot of pressure on opponents' own service games."

Asked if she would be surprised if Williams didn't win the tournament, Ivanovic laughed and said, "Yeah, very."

Williams's level of play here is particularly impressive given the physically and emotionally draining summer of work she put in.

She won singles and doubles titles (with her sister Venus) at both Wimbledon and the Olympics. Yet here she is at the final Grand Slam of the year mowing down the competition. Again.

Still, Williams, who ranks fourth all-time among women on the Grand Slam titles list, doesn't feel she's played her best yet.

"I feel like I'm going to get more focused and serious and start playing Serena tennis in the next couple of rounds — if I get to play two rounds," she said. "That's my goal.

"I didn't think I came into this tournament playing my best, but I definitely played better in the last two matches. I hope I have two matches left, and, you know, give 200 percent."

Follow Adam Zagoria on Twitter @AdamZagoria for coverage of the U.S. Open all tournament long.