Spanish eighth seed David Ferrer ousted America's John Isner in straight sets to reach the Australian Open quarter-finals without dropping a set on Monday.

Ferrer won 6-4, 6-4, 7-5 in two hours, four minutes on Hisense Arena to set up his sixth appearance in the last eight, where he will meet either Andy Murray or Bernard Tomic.

"The most important thing is I'm in the quarter-finals, playing very well without losing a set, so it's important for my next match," said Ferrer.

Ferrer, 33, ended Australian veteran Lleyton Hewitt's career en route to his eighth career meeting with the big-serving Isner, who was bidding to reach the last eight for the first time.

Solitary breaks in the first and second sets were enough for Ferrer to move to a two sets to love lead before they fought to 5-5 in a tense third set.

However the pressure told on Isner, who was looking to become the first American into the men's quarter-finals since Andy Roddick in 2010, and he was finally broken when he put a forehand wide.

Ferrer needed no further invitation and after setting up three match points on his serve, he won it when he successfully challenged a backhand which was initially called long.

"I'm feeling really good, I returned everything and the most important thing is, I enjoyed playing tennis on this court," said the Spaniard.