Juan Del Potro sets up Auckland Classic semi-final with David Ferrer

Juan Martin del Potro kept his Australian Open preparations on track with a 7-6(4) 6-3 win over Russia's Karen Khachanov in the Auckland Classic on Thursday, setting up a semi-final meeting with David Ferrer.

Former U.S. Open champion Del Potro fired down 11 aces and did not face a break point during the one hour, 33 minutes match.

The 29-year-old second seed, who won the tournament the last time he played in it in 2009, will now return to the top 10 in the ATP rankings on Monday for the first time since August 2014 after struggling with injuries over the past few years.

Waiting for Del Potro in the last four will be Spaniard Ferrer, who brushed aside ATP NextGen Finals champion Chung Hyeon of South Korea 6-3 6-2.

Ferrer is yet to drop a set in Auckland and has shown glimpses of his old form that saw him win the tournament in 2007, 2011, 2012 and 2013.

"I tried to play consistent and aggressive because with Chung, he plays with power, and it`s never easy," Ferrer said in a court-side interview. "He has a really great future."

Ferrer's countryman Roberto Bautista Agut will play Dutchman Robin Haase in the other semi-final.

2016 champion Bautista Agut defeated Czech Jiri Vesely 7-6(1) 6-2 in the last eight while Hasse beat Peter Gojowczyk of Germany 6-4 6-4.