Rafa Nadal could well come unstuck against the mercurial Fabio Fognini.
Andy Murray came back from two sets down to beat Adrian Mannarino and he now faces Thomaz Bellucci. The Brazilian left-hander is back in the world's top 30 for the first time in four years and his serve has been a potent weapon this week at Flushing Meadows. He won their only previous meeting back in 2011, admittedly on clay, but he certainly has the talent to test the Scot. Murray showed again last night how effective he is in adversity, but Bellucci to win a set at 12/5 is definitely worth a bet.
Diego Schwartzmann had his chances against Rafa Nadal but failed to take them so the Spaniard is still hanging in there. We'll try again to get him beat with our friend Fabio Fognini. The Italian scored his first two wins over Nadal earlier this season before losing 7-5 7-5 in the Hamburg final in which Fognini had a good old bark at Nadal during a changeover for slow play - well worth looking up on the internet. There should be fireworks and we'll go for Fognini to win a set at 8/13, and the match at 10/3.
Johanna Konta scored the biggest win of her career yesterday to put out Wimbledon runner-up Garbine Muguruza and it's a mystery that she had won just one Grand Slam match before this week. She has a big serve and big groundstrokes and wins over Yanina Wickmayer and Kirsten Flipkens to take the Vancouver ITF title last month showed she was in great shape. I almost put up Konta to beat Muguruza with the Spaniard in such poor form of late so I sincerely hope this isn't a case of turning up for the funeral after missing the wedding. But Andrea Petkovic has not reached the fourth round in New York since 2011 and I'm backing Konta at 13/8 to continue that sequence.
Victoria Azarenka struggled against an inspired Yanina Wickmayer but came up with the big points when it mattered. She is so good at Flushing Meadows and were it not for Serena Williams she would have two, maybe three US Open titles by now. She also has a perfect 4-0 record against third-round opponent Angelique Kerber including a 6-0 6-3 thumping in Doha in February. I still have doubts about the twice runner-up going all the way after a thigh injury, but she should prove too strong for the German and 7/5 about a straight sets win is more than fair.
My outright pick Simona Halep had to work hard against Kateryna Bondarenko who is returning to something like her best. But I expect her to have an easier time against Shelby Rogers who has strung together a couple of wins after a poor season. The Romanian looks good at 10/11 to cover the -6.5 game handicap, and I'll also be having a play on Halep winning sets 6-0 and 6-1.