New Delhi, Sep 08 (ANI): World number one Serena Williams swept past good friend Caroline Wozniacki of Denmark 6-3 6-3 in the US Open final to win her 18th grand slam title. It was the third straight and sixth US Open crown for the 32-year-old American. Having failed to get beyond the last 16 of the year's first three slams, Williams sailed through the US Open without dropping a set, finishing off Wozniacki in a snappy 75 minutes. For the 10th seeded Wozniacki, back in a grand slam final for the first time in five years, it was another frustrating end to a promising fortnight as she once again left Flushing Meadows empty handed, a major title still beyond her grasp.