Serena Williams was quickly out of the blocks on Sunday and that pretty much put paid to my decision to back Madison Keys. The 20-year-old showed flashes but the world number one was too good and I am confident she will go on to complete the first calendar Grand Slam since 1988.

Andy Murray went out to an inspired Kevin Anderson and I cannot see the Briton adding to his major tally until he improves that second serve of his. The South African made mincemeat of it and Murray was always up against it although there was a moment in the third set when he really looked like kicking on.

Anderson is clearly more than just a serve and he has won his last four meetings with quarter-final opponent Stan Wawrinka. The Swiss has looked disinterested at times in this tournament and he might well have preferred to meet Murray at this stage. Anderson to win at 5/4 has to be the play here.

Jo-Wilfried Tsonga brushed aside Benoit Paire in the previous round and he is yet to drop a set this fortnight at Flushing Meadows. He faces defending champion Marin Cilic in the quarters with the Croat winning their last three meetings. But Tsonga looks a different proposition this fortnight and he is a worthy favourite this time. I'm happy to take 11/10 or better about Tsonga -1.5 sets on the handicap.

I'm struggling to come up with a bet on the women's side with fitness doubts over Simona Halep and I'm not tempted by the all-Williams clash. And while I expect Kristina Mladenovic to beat Roberta Vinci, she might find the Italian a tricky opponent.

Petra Kvitova was pushed hard by Johanna Konta but she should be too strong for Flavia Pennetta who is in the quarter-finals at Flushing Meadows for the sixth time. Kvitova has won their last three meetings and while the last of these was back in 2012, it's a good match-up for the Czech and 10/11 about a straight sets win looks fair.

Kevin Anderson to beat Stan Wawrinka - 1pt @ 5/4Lost 1pt
Jo-Wilfried Tsonga -1.5 sets v Marin Cilic 1pt @ 23/20 - 1pt @ 23/20Lost 1pt
Petra Kvitova to beat Flavia Pennetta in straight sets - 1pt @ 10/11Lost 1pt