Serena Williams eased past Madison Keys in straight sets to reach the quarter-finals of the US Open on Sunday night and keep her hopes of a calendar Grand Slam alive.
The all-American clash saw the six-time US Open winner defeat Keys 6-3, 6-3 in a touch over an hour on the hard courts in New York City.
The first set was tense affair as both players held serve well until an unforced error from Keys lead to a break point for Williams in the eighth game, which she grasped with both hands to take a 5-3 lead, after which she served out the set.
Keys came out firing in the second set where she would amass 18 winners but her unforced error count was too high, costing her a break and giving Williams 5-3 lead.
The world number 19 still had a chance to get back on serve though, however, a lapse of concentration would lead to her sixth double fault and hand the win to Williams, who moves to an incredible 52-2 for the 2015 season.
The win sets up a mouth-watering match against her elder sister Venus in the round of 16 next week.
Earlier in the day, Venus powered past qualifier Anett Kontaveit 6-2, 6-1 in just 51 minutes to book a place in her eleventh US Open quarter-final and her first since 2010.
The sisters have faced each other 26 times, with Serena winning the head to head 15-11. However, Venus did defeat her younger sister as recently as 2014 in the semi-finals of the Canadian Masters.