Caroline Wozniacki squandered four match points before eventually sealing her place in the quarter-finals of the Brussels Open in Belgium after overcoming world No. 85 Varvara Lepchenko.

24638 - Wozniacki labours into quarters as Jankovic exits

The world No. 1 immediately found herself a break down before battling back to win the opening set. Wozniacki appeared to struggle against an unpredictable opponent, but looked to be on course for a routine victory after a break in the second, but she was pegged back by a determined Lepchenko.

Serving to stay in the match, the American saved two match points to take the second set to a tiebreak, but despite needing all three match points, Wozniacki showed her battling qualities to eventually seal a 6-4 7-6(5) victory after nearly two hours on court.

The Dane will now meet fifth seed Yanina Wickmayer who triumphed in an all-Belgian clash against Alison van Uytvanck. The sixth seed was given a scare by the Belgian teenager, ranked over 400 places below her but held her nerve to clinch a 7-6(2) 6-4 win.

However, fourth seed Jelena Jankovic was sent crashing out by Sweden's Sofia Arvidsson. The Serb won the opening set, but was humbled 3-6 6-3 6-3. Arvidsson will now meet China's Peng Shuai, who eased past Abigail Spears 6-2 6-0.

Second seed Vera Zvonareva survived a wobble to progress to the quarter-finals with a 2-6 6-4 6-3 win over Kazakh qualifier Galina Voskoboeva.

French Open champion Francesca Schiavone also progressed to the last eight, but had to fend off a valiant effort from Irina Falconi. The fourth seed was made to work hard for her 6-4 6-4 win over the world No. 116.