LONDON, July 8 (Reuters) - Coco Vandeweghe continued her seamless progress at Wimbledon as she booked her spot in the fourth round with a 6-2 6-4 win over fellow American Alison Riske on Saturday.
The 24th seed, who is coached by former men's winner Pat Cash, has yet to drop a set in her three opening matches and is looking a good bet to defy the odds as the women's draw becomes increasingly hard to predict.
While her form has swung between the extremes of a semi-final run to the Australian Open in January and a first round exit at the French Open in May, she has some pedigree on grass, having reached the quarter-finals at Wimbledon in 2015.
She has hired Cash hoping he can give her an extra edge, 30 years after the head-band wearing Australian lifted the trophy at the All England Club.
She broke twice to race through the opening set against Riske and twice more at the start of the second to take a 4-0 lead.
The wheels threatened to come off at that stage as her compatriot fought back to level at 4-4.
Vandeweghe, however, steadied her nerves to break again and set up three match points with an ace before checking out with a service winner. (Reporting by Toby Davis; editing by Clare Lovell)