The Americans claimed a 21-15, 21-13 win over Germany’s Teresa Mersmann and Isabel Schneider at the Lindner Family Tennis Center to move to the brink of another World Tour final.

They have already won three of the five tournaments they have contested this season, earning a medal in four and losing only two out of 33 matches.

“I’m happy with it,” said Walsh Jennings, a triple Olympic gold medallist who will be looking for a fourth consecutive title at Rio 2016.

"I don’t want to put a number on it but I know we have better in us.

"I’m looking forward to having that come out all day tomorrow.

"But it’s been really good.

"I feel like our energy is really positive.

"I feel like we’re really cohesive in defense, which is my favourite part of the entire game, and I feel like we’re doing what we want to do so we’re finding our rhythm.”

The US pair will meet fourth-seeded Elsa Baquerizo and Liliana Fernandes of Spain in the semi-finals after they won their quarter-final against another American duo - Lauren Fendrick and Brooke Sweat - 21-12, 21-17.

China's Chen Xue and Xinyi Xia are also through to the last four after a 21-19, 21-8 win over Germany’s Katrin Holtwick and Ilka Semmler.

They will play Dutch duo Jantine van der Vlist and Sophie van Gestel, who beat China's Fan Wang and Yuan Yue, 19-21, 21-14, 15-10.

In the men's quarter-finals, Americans Ryan Doherty and John Mayer upset top-seeded compatriots Jake Gibb and Casey Patterson 21-19, 17-21, 15-13.

They will play Brazil's Gustavo Carvalhaes and Saymon Barbosa, 21-19, 22-20 winners over Americans John Hyden and Tri Bourne.

Another home pairing, second seeds Phil Dalhausser and Nick Lucena, saw off Australia’s ninth-seeded Isaac Kapa and Christopher McHugh 21-13, 21-15.

Their prize is a clash with Josh Binstock and Sam Schachter, who won an all Canadian quarter-final against Grant O’Gorman and Sam Pedlow, 21-19, 18-21, 15-12.

The semi-finals and finals will be played in both competitions tomorrow.