Serena beats Vaidisova, advances to semis

KEY BISCAYNE, Fla. -- Three-time champion Serena Williams reached the semifinals, beating No. 8-seeded Nicole Vaidisova 6-1, 6-4 at the Sony Ericsson Open Wednesday.

Williams will play for the fourth day in a row Thursday night
when she faces No. 14 Shahar Peer. A 19-year-old corporal in the
Israeli Army, Peer nearly pulled off an upset against Williams in
the quarterfinals of the Australian Open in January, losing the
third set 8-6.

One day after routing Maria Sharapova, Williams won her first
set in 25 minutes but struggled through much of the second. She
trailed Vaidisova 3-4, love-40, then won 13 of the final 14 points,
including aces on the final two points.

"I just went erratic," Williams said. "I started missing
shots and made a lot of unforced errors. My ball started flying.
There are no excuses. I just starting playing crazy."

The victory means Williams will climb into the top 15 in next
week's rankings. She started the year 95th.

Peer advanced to the semifinals by winning the first nine games
and beating No. 24 Tathiana Garbin 6-0, 6-3.

Peer is 0-2 against Williams, but was two points from victory
when they met in Melbourne.

"What a match I had down there with her," Williams said. "She
has made a lot of great progress."

The other women's semifinal Thursday will be between top-ranked
Justine Henin and Anna Chakvetadze. With second-ranked Sharapova's
loss Tuesday, Henin is assured of remaining No. 1 next week.