MELBOURNE, Australia – US Open mixed doubles champions Bethanie Mattek-Sands and Jamie Murray won through to the quarterfinals of the Australian Open competition with a 6-4, 6-4 victory over Kristina Mladenovic and Robert Lindstedt.

A solitary break of serve in the fifth game of the opener was enough for the American-British partnership to secure the set, in which they looked totally in command on service, not giving up a single break point.

Their opponents hit back immediately at the start of the second, breaking at the first opportunity, but this advantage lasted a matter of minutes as they immediately squandered serve.

Mattek-Sands and Murray looked particularly dangerous when given second serves to attack, winning nearly 50% of such situations in the second set while not giving up a single point in reciprocal instances.

It was little surprise, then, that they found another breakthrough, this time in the seventh game, and then held on to seal a place in the last eight.

Wildcard partnership Astra Sharma and John-Patrick Smith lie ahead for Mattek-Sands and Murray after the Australian duo saw off the challenge of Andreja Klepac and Edouard Roger-Vasselin on Monday, 6-4, 7-5.

The home hopes of Jessica Moore and Andrew Whittington were dashed, however, by María José Martínez Sánchez and Neal Skupski, who recorded a 6-4, 6-1 victory.

Meanwhile, there was success for the No.6 seeds Abigail Spears and Juan Sebastian Cabal, who needed just 46 minutes to beat Demi Shuurs and Matwe Middelkoop. The victorious partnership hit 19 winners and made just one unforced error in a 6-1, 6-2 win.