London: Serena Williams set up a titanic Wimbledon fourth round showdown with sister Venus as the world number one staged a dramatic final set fightback to beat Britain's Heather Watson 6-2, 4-6, 7-5 on Friday.


US player Serena Williams smashes a return against Britain's Heather Watson during their women's singles third round match on day five of the 2015 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London. Pic/AFP 

Williams, bidding for a sixth Wimbledon title and a calendar Grand Slam, was on the brink of a humiliating third round exit when Watson served for the match at 5-4 in the final set. But Serena, who had trailed 3-0 in the decider, showed why she has won 20 Grand Slam titles as she broke back before finally sealing an epic escape in two hours and 14 minutes in front of an enthralled 15,000-strong crowd on Centre Court.