Vandeweghe, who hired Cash as her coach in the leadup to the tournament after splitting with Craig Kardon, stormed into the last 16 with 6-2 6-4 win over fellow American Alison Riske.
In women's draw in which all 16 survivors will fancy their chances, Vandeweghe's credentials stack up well.
The 24th seed has yet to drop a set in her three opening matches and hits winners for fun -- 87 so far.
She had a brief wobble against 46th-ranked Riske but was comfortably in control on Saturday.
While her form this year 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, three decades since the head-band wearing Australian lifted the trophy at the All England Club and after her build-up to Wimbledon was marred by a split with Kardon.
"He's (Cash) present at all my practices, all my matches. He's made a commitment to the working team. So I think a pretty big impact," she told reporters on Saturday.
Vandeweghe has many of the tools needed to succeed on grass, principally a booming serve that regularly approaches the 120mph mark. In her three victories at Wimbledon this year, she has won 88 percent of points on her first serve.
She also has form when it comes to causing an upset as she showed by beating world number one Angelique Kerber at the Australian Open in January.
Against Riske, she broke twice to race through the opening set 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 another service winner.
With the pregnant Serena Williams missing this year's Wimbledon and many of the other top women's players struggling for form or fitness, the draw is opening up.
"I think there is some very solid depth (in the women's game) of players that can make an impact against a top player," she said. "I'm an example of that myself."
(Reporting by Toby Davis; editing by Clare Lovell and Martyn Herman)
Share
