Elina Svitolina booked her place in the semi-finals of the WTA Finals in Shenzhen after beating Wimbledon champion Simona Halep 7-5, 6-3. The Ukrainian, who won the event last year in Singapore, is now on a seven-match winning streak at the WTA Finals, is the first player into the semi-finals. Svitolina got off to a fine start, winning the first three games of the match, before being pegged back by Halep. After moving 6-5 up, Svitolina broke the Halep serve to love to close out the first set. Halep went ahead briefly in the second set, breaking to go 2-1 up, but won only one of the remaining six games in the match. Svitolina was forced to save two break points when attempting to serve for the match but held her nerve to add to her opening win over Karolina Pliskova. Pliskova meanwhile, still has a chance to qualify for the semi-finals despite losing her opening match after beating Bianca Andreescu. The Canadian youngster enjoyed a bright start to the encounter, winning the first two games before injuring her knee. That effectively ended the match as a contest and Andreescu won just one more game before retiring after losing the first set 6-3.