Karolina Sprem, the Croatian 19-year-old who sent Venus Williams out of the tournament in the second round, continued to blaze a trail yesterday as she toughed it out 7-6, 7-6 against the more experienced American Meghann Shaughnessy.

Sprem, who knocked Williams out after a now infamous tie-break in which umpire Ted Watts called the wrong score, continued to face criticism over not interjecting to correct the error. American second seed Andy Roddick sided with the Williams camp saying Sprem should have handed back the point. But Sprem is proving to be a durable individual and not ready to fold on or off the court.

"I was confused. I didn't know what was happening. If I didn't know the score then maybe she (Venus) know. But if she didn't know then the umpire is supposed to know. Bad luck for him. But we have so many people on the court and they need to know the score, not me in this moment. So this is behind me and I don't want to talk about it."

Although she has yet to win a tour title, Sprem has reached a quarter-final in Miami and three semi-finals, in Canberra, Antwerp and Berlin, this year and last year dropped her ranking from 273 to 59.

She is also making a name for herself as a tie-break winner. Having beaten Williams in two sets with tie-breaks, she carried the form through, allowing Shaughnessy only two points in the second set decider.

"The fourth time I win in the tie-break this week, so I'm tiebreak specialist. And it's okay," she added unperturbed.

Eye-catching as Sprem was, it remains difficult to keep the larger figures of Serena Williams, Amelie Mauresmo and Jennifer Capriati from the horizon. All three advanced with varying degrees of ease, Capriati struggling in the first set against Natalie Dechy 7-5 before routing her 6-1 in the second.

Mauresmo was imposing and clinical against Ludmila Cervanova, allowing her one game in the first set and four in the second, while Williams cruised along against Magui Serna from Spain.

Williams opened with a 6-4 first-set win before noticing that the sky was darkening with possible rain on the way. She then picked up her pace to a murderous level and smacked Serna into the locker-room 6-0.

"I saw the attendants coming. Looked like they were going to cover the court at 4-0. I was like 'oh, boy'," said Williams. "I don't want to be five-love, 40-15 and have to come off the court. That would have been really unfortunate."

Williams found a better rhythm than in her previous matches and took a little bit off her normally ferocious pace. It paid dividends.

"For years my dad's been telling me 'take the pace off. Don't hit them 120 if you can hit them 110'. First time in 10 years I decided, 'okay, hmmm . . . it finally clicked. It worked every time. I took a lot of pace off and got it in."

Even taking some muscle off her shots will not put Williams in the minor league of hitters, rather, it should send a chilling message to the rest of the draw that she is now beginning to think her way through matches. Traditionally it has been route one and if that doesn't work, just hit it harder.

Challenging for her third successive title, she could, if she wins this year, become only the third player along with Martina Navratilova and Steffi Graf to have done so in the Open era (Billy Jean King also won three but her spread was 1966-68, just prior to the game going professional).

That alone is something to make the number one seed take dad's advice.

Meanwhile, on Saturday the United States named 47-year-old Navratilova in their tennis team for the Athens Olympics. She will make her Olympic debut in the women's doubles with Lisa Raymond.