Meghann Shaughnessy reached the quarter-finals of the Sparkassen Cup with a surprise 6-2 6-4 victory against second seed Jelena Dokic in Leipzig.

The American needed just 57 minutes to record her first ever win over Dokic, who has failed to progress beyond the second round of a tournament just twice all year.

World number one Serena Williams suffered a temporary blip but recovered to beat Anca Barna 6-1 3-6 6-1.

German qualifier Barna took advantage of a lapse in concentration to become just the third player to take a set off Williams since the French Open.

But Williams brushed her aside in the decider to book her place in the last eight.

Belgian third seed Justine Henin survived a tough test against Iveta Benesova of the Czech Republic as she came back to win 6-7 7-6 6-2.

Seventh seed Silvia Farina Elia was also taken to three sets in her first-round match, beating fellow Italian Francesca Schiavone 6-4 6-7 6-2.

Alexandra Stevenson beat Denisa Chladkova of the Czech Republic 6-4 4-6 6-2.

And fifth seed Daniela Hantuchova also made it into the last eight, although she needed a third set tie-break to beat Italy's Rita Grande.

Wednesday's Sparkassen Cup results

First round