Kim Clijsters is safely through to the quarter-finals of the women's Olympic singles following a straight-sets victory over Serbian 11th seed Ana Ivanovic.

The Belgian broke just the once in the opening set on her way to a 6-3 triumph.

Following a mammoth second game which Clijsters eventually held, the four-time Grand Slam winner then broke as she closed out the match 6-4.

Clijsters will now face either Russian third seed Maria Sharapova or German 15th seed Sabine Lisicki for a place in the semi-finals.