Tennis: Serena made to work by Sakkari

Serena Williams was pushed all the way by Maria Sakkari Maria Sakkari in a tight three-set contest in the fourth round of the US Open. Williams won the first set 6-3, but was pegged back by the Greek in the second, who edged it in a tiebreak. However the American secured a crucial break of serve in the eighth game of the decider, and served out the match to claim a hard-fought 6-3 6-7 6-3 win. Williams, who is in search of a 24th Grand Slam title, will face Bulgarian Tsvetana Pironkova in the last-eight.