Former World No Ones Venus Williams and Serena Williams set up a dream semifinal clash with fluent victories in the $600,000 Bangalore Open here on Friday.

While Venus suffered a minor hiccup late in the match before overcoming Vera Zvonareva of Russia 6-4, 6-3, Serena was ruthless in her demolition of Anastasia Rodionova 6-1, 6-4 in the other quarterfinals.

The spectators’ focus wasn’t on the impending mouth-watering clash. Instead they were talking about the unheralded Zi Yan's stunning 6-3, 3-6, 6-3 win over top seed and world No 4 Jelana Jankovic in a late evening clash.

The conqueror of eighth seed Maria Kirilenko in the opener, the 23-year-old Chinese has been improving with each outing. On Friday, Yan was at her brilliant attacking best. Barring the second set, where Jankovic came out firing despite a shoulder niggle, it was Yan who called the shots for the better of the tie that lasted a just over two hours.

"I was making a lot of errors and was not feeling the ball at all," said Jankovic. "Too many bad mistakes, too many wrong options. I just gave her the match," she added.

Yan would beg to differ though. The Chinese girl, winner of a WTA Tour title, came out firing on all cylinders. Predominantly a doubles player, she proved she can be a handful in singles as well. Kirilenko will vouch for that! Yan was solid from the back of the court, hitting flat and deep, forcing Jankovic into errors.

Decisive break

She had a chance to break Jankovic in the sixth game of the opening set, but the Serbian dug deep into her reserves to hold the serve. But Yan got the decisive break in the eighth game and closed out the set in the next.

Down and seemingly out, Jankovic needed to come up with something spectacular, and quickly. And she did.

Jankovic came out aggressive and made some great winners to take the set and push the issue to the decider.

In the final set, Yan upped her game while Jankovic's fell apart. The Chinese rediscovered her form and strokes to jump to a 4-0 lead, while Jankovic fell into rut one again.

The Serbian managed to break Yan twice, but just didn't have enough weapons on the day to alter the script.

Jankovic saved two match points in the eighth game, but Yan closed out the set and match in the next. "It's a big win for me. It's my first Tier II semifinals," said and elated Yan. "I was not aggressive in the second set, but I got back into the groove quickly," added the Chinese.

Yan will have to be at her aggressive best in her semifinal against Switzerland's Patty Schnyder. The Swiss lady rallied brilliantly to stop giant-killer Akgul Amanmuradova 4-6, 6-4, 7-6 (7-1) on a windy afternoon.

Meanwhile, Venus came up with a much-improved show to outclass Zvonareva. Cutting down on the errors and serving much better, Venus shot to a quick 5-1 lead. But a slew of errors in the seventh allowed Zvonareva to pull one back. The powerful Russian broke Venus again in the ninth.

The American took the opening set with the help of a net-chord, but she needed no such in the second to set up a clash with Serena. "She (Venus) is a tough opponent," Serena said about her sister. "I was hoping she would hurt a leg today," she joked when asked about the meeting.

Semifinal line-up: Patty Schnyder (Sui) vs Zi Yan (Chn); Venus Williams (US) vs Serena Williams (US).

Results: Singles (Quarterfinals): Patty Schnyder bt Akgul Amanmuradova (Uzb) 4-6, 6-4, 7-6 (7-1); Venus Williams bt Vera Zvonareva (Rus) 6-4, 6-3; Serena Williams bt Anastasia Rodionova (Rus) 6-1, 6-4; Zi Yan bt Jelena Jankovic (Srb) 6-3, 3-6, 6-3.

Doubles (Semis): Yung-Jan Chan (Tpe)/ Chia-Jung Chuang (Tpe) bt Ekaterina Dzehalevich (Blr)/ Monica Niculescu (Rom) 6-1, 7-5.