Unicef Open: Radwanska advances as Clijsters retires injured

Poland's Urszula Radwanska advanced to the final of the s-Hertogenbosch grasscourt tournament on Friday after Belgian Kim Clijsters pulled out of their semi-final clash citing injury.

Tournament organisers said in a statement that former world number one Clijsters had withdrawn before the tie with a "stomach injury".

"Together with her team and on medical advice she has decided not to play her semi-final match against Urszula Radwanska," the statement added.

Clijsters had been making her return this week after not playing since March because of a right hip injury.

The 28-year-old was champion in this pre-Wimbledon event in 2003.

Clijsters, a four-time Grand Slam title winner who will retire after the US Open, had been drawn earlier Friday to begin her Wimbledon campaign against fellow former world number one Jelena Jankovic of Serbia.