<p class="title">Novak Djokovic's third-round struggle with defending champion Grigor Dimitrov was halted by rain, forcing the pair to come back on Friday at the ATP-WTA Cincinnati Masters.</p>.<p class="bodytext">Officials called a halt to a frustrating day on which Roger Federer was never able to take the court for his third-round match against Leonardo Mayer.</p>.<p class="bodytext">Wimbledon champion Djokovic is vying to break through for a first Cincinnati win after coming up empty in five finals. He lost the first set 2-6 and won the second 6-3 when rain stopped the contest for 90 minutes.</p>.<p class="bodytext">When play resumed, Djokovic edged ahead 2-1 in the third, but another storm rolled in and organizers called a halt.</p>.<p class="bodytext">Earlier, Simona Halep and Juan Martin del Potro at last managed to complete weather-delayed second-round victories.</p>.<p class="bodytext">World number one Halep took advantage of an early afternoon respite from the weather to finish off a 4-6, 6-3, 6-3 victory over Ajla Tomljanovic.</p>.<p class="bodytext">Halep, clearly frustrated when the match was halted at 3-3 in the third on Wednesday night, won three straight games to finish off the victory in 10 minutes -- just in time for drizzle to set in.</p>.<p class="bodytext">Argentina's world number three del Potro had played just six points in the first game of his postponed second-round match against Chung Hyeon before the rain came again.</p>.<p class="bodytext">But the weather cleared long enough for del Potro to polish off a 6-2, 6-3 win over the South Korean to set up a meeting with Australian Nick Kyrgios for a place in the quarterfinals - a match originally set for Thursday night but now on tap for Friday.</p>.<p class="bodytext">Two men's quarter-inalists were decided as Milos Raonic defeated Denis Shapovalov 7-6 (8/6), 6-4 -- avenging a loss to his young Canadian compatriot in Madrid three months ago.</p>.<p class="bodytext">Pablo Carreno Busta also advanced, beating Robin Haase of the Netherlands 6-4, 6-2.</p>.<p class="bodytext">In women's third-round action, reigning US Open champion Sloane Stephens was eliminated while Madison Keys, runner-up at Flushing Meadows last year, moved on. Belgian Elise Mertens scored the second top five win of her career, beating Stephens 7-6 (10/8), 6-2 while Keys rallied to defeat fourth-seeded Wimbledon champion Angelique Kerber 2-6, 7-6 (7/3), 6-4.</p>.<p class="bodytext">Keys fired 55 winners with 44 unforced errors against the German, who is playing her first hardcourt tournament in the buildup to the US Open.</p>.<p class="bodytext">Keys next faces Aryna Sabalenka of Belarus, who upset French sixth seed Caroline Garcia 6-4, 3-6, 7-5. Petra Kvitova, who toppled Serena Williams in the second round, reached the last eight with a 6-4, 6-2 win over France's Kristina Mladenovic.</p>
<p class="title">Novak Djokovic's third-round struggle with defending champion Grigor Dimitrov was halted by rain, forcing the pair to come back on Friday at the ATP-WTA Cincinnati Masters.</p>.<p class="bodytext">Officials called a halt to a frustrating day on which Roger Federer was never able to take the court for his third-round match against Leonardo Mayer.</p>.<p class="bodytext">Wimbledon champion Djokovic is vying to break through for a first Cincinnati win after coming up empty in five finals. He lost the first set 2-6 and won the second 6-3 when rain stopped the contest for 90 minutes.</p>.<p class="bodytext">When play resumed, Djokovic edged ahead 2-1 in the third, but another storm rolled in and organizers called a halt.</p>.<p class="bodytext">Earlier, Simona Halep and Juan Martin del Potro at last managed to complete weather-delayed second-round victories.</p>.<p class="bodytext">World number one Halep took advantage of an early afternoon respite from the weather to finish off a 4-6, 6-3, 6-3 victory over Ajla Tomljanovic.</p>.<p class="bodytext">Halep, clearly frustrated when the match was halted at 3-3 in the third on Wednesday night, won three straight games to finish off the victory in 10 minutes -- just in time for drizzle to set in.</p>.<p class="bodytext">Argentina's world number three del Potro had played just six points in the first game of his postponed second-round match against Chung Hyeon before the rain came again.</p>.<p class="bodytext">But the weather cleared long enough for del Potro to polish off a 6-2, 6-3 win over the South Korean to set up a meeting with Australian Nick Kyrgios for a place in the quarterfinals - a match originally set for Thursday night but now on tap for Friday.</p>.<p class="bodytext">Two men's quarter-inalists were decided as Milos Raonic defeated Denis Shapovalov 7-6 (8/6), 6-4 -- avenging a loss to his young Canadian compatriot in Madrid three months ago.</p>.<p class="bodytext">Pablo Carreno Busta also advanced, beating Robin Haase of the Netherlands 6-4, 6-2.</p>.<p class="bodytext">In women's third-round action, reigning US Open champion Sloane Stephens was eliminated while Madison Keys, runner-up at Flushing Meadows last year, moved on. Belgian Elise Mertens scored the second top five win of her career, beating Stephens 7-6 (10/8), 6-2 while Keys rallied to defeat fourth-seeded Wimbledon champion Angelique Kerber 2-6, 7-6 (7/3), 6-4.</p>.<p class="bodytext">Keys fired 55 winners with 44 unforced errors against the German, who is playing her first hardcourt tournament in the buildup to the US Open.</p>.<p class="bodytext">Keys next faces Aryna Sabalenka of Belarus, who upset French sixth seed Caroline Garcia 6-4, 3-6, 7-5. Petra Kvitova, who toppled Serena Williams in the second round, reached the last eight with a 6-4, 6-2 win over France's Kristina Mladenovic.</p>