TORONTO, Canada — World number two Elena Rybakina battled her way into the WTA Canadian Open quarter-finals on Sunday, while fourth-ranked Coco Gauff cruised into the last eight. Kazakhstan’s Rybakina outlasted Russian Liudmila Samsonova 6-4, 4-6, 6-4 after two hours and 49 minutes, before American Gauff eliminated Russian teen qualifier Alina Korneeva 6-3, 6-1 in
