LUXEMBOURG — Canada's Eugenie Bouchard advanced to the semifinal of the Luxembourg Open tennis tournament on Thursday when her quarterfinal opponent, Andrea Petkovic of Germany, retired with a leg injury in the second set.

Petkovic was leading by a set after she broke Bouchard in the final game of the set to take it 6-4.

Bouchard, from Westmonut, Que., jumped out to an 2-0 early lead in the second with dominant service play. Petkovic called the trainer, then played tentatively through two more games before withdrawing with Bouchard leading the set 4-0.

Bouchard had nine aces in the match and was good on 73 per sent of first serves.

The Canadian, who has won six matches in a row for the first time since 2014, faces top seed Julia Goerges in the semifinals.