MELBOURNE, Australia -- Venus Williams slammed down powerful aces in advancing to the semifinals of the Australian Open.

	Daniela Hantuchova fell to 0-4 against Venus Williams in her career.

After spectators loudly called some of her shots out, Williams responded with a burst of winners midway through the first set that helped carry her to a 6-4, 6-3 victory over seventh-ranked Daniela Hantuchova on Tuesday.

Williams also served six aces at speeds of up to 125 mph, shown as 201 kilometers per hour on the board.

"I don't know if I served well, but did everyone see the 201?" Venus asked in a post-match interview. "I was surprised when I saw that speed. I got a bit distracted, so I said, 'Venus, focus back on the match.' "

She's been concentrating on accuracy over speed since producing the fastest recorded serve in women's tennis, clocking 127 mph at Zurich in 1998. But her powerful serve had her thinking of changing her tactics.

"Now I'm going to start trying to see if I can serve it even bigger than the record," Williams said.

Williams got match point with a backhand crosscourt winner on the run, losing her earring in the process. She replaced the jewelry, composed herself and won it on the next point when Hantuchova sent a backhand long.

Venus was testing the limits of her serve and groundstrokes, her five double faults and 32 unforced errors giving Hantuchova some free points and contributing to a dropped service game in each set.

"I was fortunate to get through," Williams said. "I don't think Daniela played as well as she wanted to today."

She will meet No. 5 seeded Justine Henin-Hardenne in the semifinal after the Belgian beat Virginia Ruano Pascual 6-2, 6-2.

Henin-Hardenne, who tumbled to the court with leg cramps in a 3½-hour fourth-round win over former No. 1 Lindsay Davenport on Sunday, dropped her opening service game and trailed 0-2 before she rallied to win eight in a row.

"I've played a lot of close matches against Venus. I believe in my chances and I will go on court to win the match," said Henin-Hardenne, who lost to Williams in the 2001 Wimbledon final.

A semifinal win by Williams could set up another final against her sister Serena, who is on the top half of the draw and faces Meghann Shaughnessy in a Wednesday quarterfinal. Serena is aiming for a fourth consecutive major to complete her "Serena Slam."

Hantuchova came close to beating Venus here in the third round last year, but slipped to 0-4 against the world No. 2.

In the 10th game, Hantuchova led 40-15 on serve but made errors on the next three points.

"That serve was incredible," Hantuchova said. "I have to improve the speed of my serve."