Halep sounds a warning

SINGAPORE — Simona Halep laid down an ominous marker for her rivals at the WTA Finals Sunday, demolishing rising American Madison Keys 6-2, 6-4 in the opening match of the $7 million end-of-season event. The Romanian, a finalist two years ago, looked in great touch on her return to Singapore’s purple indoor hardcourt, needing just 68 minutes to win her round-robin match against Keys in straight sets. The big-hitting Keys struggled to find her rhythm against Halep, who is one of the most tenacious counter-punchers in the game, committing 18 unforced errors and losing 13 points in a row to concede the opening set after just 27 minutes. Despite being in control, Halep also had a moment of self-doubt in the second set, and even called for her coach Darren Cahill, who told her to relax and keep playing the way she was. Halep immediately broke Keys to grab the early advantage in the second set but a sloppy service game allowed the American to draw level at 4-4. However, Halep regained her composure and broke straight back, then served out the match to go straight to the top of the Red Group standings. World number one Angelique Kerber was scheduled to play Slovakia’s Dominika Cibulkova in Sunday’s other Red Group match, with the top two players from the pool phase advancing to next weekend’s semi-finals. The four players in the White Group, Agnieszka Radwanska, Karolina Pliskova, Garbine Muguruza and last-minute qualifier Svetlana Kutznetsova, all play their opening matches Monday. Goffin suffers setback David Goffin’s hopes of qualifying for the ATP World Tour Finals suffered a setback when he lost 7-5, 2-6, 7-5 to Argentina’s Diego Schwartzman in the semifinals of the Antwerp Open Saturday. The Belgian top seed, playing in front of a home crowd, looked poised to reach the final after winning the second set but fell in a tense decider. Schwartzman will face Frenchman Richard Gasquet in the final after he recovered to beat Britain’s Kyle Edmund 3-6, 7-5, 6-2. Del Potro ends long wait Juan Martin del Potro reached his first ATP final since January 2014 Saturday with an impressive 6-4, 7-5 win over Bulgaria’s Grigor Dimitrov in the Stockholm semifinals. The world No. 63 from Argentina will face America’s Jack Sock in Sunday’s final. Sixth-seeded Sock downed German fourth seed Alexander Zverev 6-7 (4/7), 7-6 (7/4), 6-4 in the other semifinal.