( dpa )- Swede Sofia Arvidsson made the most of her lucky loser status at the Proximus Diamond Games as she upset second seed Anna Chakvetadze 6-3, 7-5 on Thursday to reach the quarter-finals.
The number 66 knocked out Russia's world number six in 79 minutes as a capacity crowd of 13,000 began to file into the Sportpaleis for a later match featuring Justine Henin.
The Belgian who tops the world rankings is playing in her home country at a Tour event for the first time in five years, taking on Bulgarian qualifier Tsvetana Pironkova.
Arvidsson improved her 2008 record to eight wins, three defeats as she moved into a Friday match with Chinese ninth seed Li Na.
Chakvetadze's defeat was a letdown after the 20-year-old claimed the Paris Indoor title last weekend. She came to Antwerp for the final edition of the event seeded to challenge Henin in the final.
The contest was filled with breaks of serve, 11 in total, with the Swede having the last word by getting past a second round for the first time this season.
Chakvetadze owns seven career WTA titles, claiming success in every final she has played so far. But the favourite failed to duplicate her Antwerp semi-final from a year ago.
In other second-round matches, qualifier Alisa Kleybanova of Russia beat Kateryna Bondarenko of the Ukraine 7-5, 3-6, 7-5 to line up against the winner from Henin and her Bulgarian opponent.
Swiss Timea Bacsinszky defeated American Julie Ditty 7-5, 6-4 and next faces third seed Daniela Hantuchova.