There was support in the US Open winner market for Serena Williams as she won her second round match at what will be her final tournament. Andy Murray also won and was backed on Betfair... The odds on Serena Williams winning the US Open women's single were slashed to 14/1 from 25/1 after the six-time champion beat world number two Anett Kontaveit to reach the third round. Williams, ranked 605th in the world and 41 next month, won 7-6 2-6 6-2 to stun the Estonian in New York. Williams, who will retire after the US Open, won the first of her 23 Grand Slam titles at Flushing Meadows in 1999. Her performances so far show she has no intention of bowing out without a fight. Next up, she will play Australia's Ajla Tomljanovic in the third round on Friday. Andy Murray backed after reaching round three The price on Andy Murray winning the men's singles was also cut to 66/1 from 80/1 after he reached the third round. Murray won his first Grand Slam when he took the US Open title in 2012 and has called it his favourite tournament. He lost the first set against Emilio Nava but fought back to win 5-7 6-3 6-1 6-0. Murray will face a huge test in the last-32 when he takes on 13th seed Matteo Berrettini on Friday. As for the other Brits at the US Open, Cameron Norrie is 25/1 to lift a first ever Grand Slam title, along with Jack Draper 80/1 and Daniel Evans 225/1, who are all still in contention. Get the best bets for both draws every day of the US Open from Dan Weston.