World number one Serena Williams recovered from a shaky start to beat American wild card Bethanie Mattek-Sands in thrilling three sets to reach the fourth round of the US Open.
The 21-time Grand Slam champion overcame her compatriot Bethanie 3-6, 7-5, 6-0 in a match that lasted one hour and 49 minutes.
Reflecting on her performance, Serena admitted that Bethanie came out well, adding that she had to adapt to her opponent's game and was finally able to get some rhythm going towards the end of the second set, the Guardian reported.
Although Bethanie produced a gutsy show in the first two sets, she failed to sustain the momentum as Serena secured the decider without dropping a point in mere 25 minutes.
Serena will next face another American, Madison Keys, in the fourth round and she now stands four victories away from becoming the first player since 1988 to complete the calendar-year Grand Slam.