Serena Williams weeps in Toronto

Serena Williams wept as she retired just after four games in the Rogers Cup final due to an upper back injury, handing unseeded teenager Bianca Andreescu the title in her homeland.

Williams, attempting to claim her first WTA Tour title since returning from maternity leave, was a break down at 3-1 in the first set in Toronto on Sunday when she declared she was unable to continue.

The 23-time grand slam singles champion sobbed as she was embraced by the 19-year-old Andreescu, after succumbing to an injury setback just a fortnight before the US Open gets under way.

Andreescu becomes the first home winner of the WTA Premier tournament since Faye Urban beat Vicki Berner in an all-Canadian final 50 years ago.

Powerful Ontario native Andreescu will rise to 14th in the world on Monday, replacing Amanda Anisimova as the highest-ranked teenager in the women’s game.

– PM News