Del Potro to play Baghdatis in Sydney tennis quarters

Juan Martin del Potro brushed aside Lukasz Kubot Wednesday to reach the quarter-finals of the Sydney International, as the Argentine edges closer to cracking the top ten rankings.

World number 11 del Potro, clawing his way back after a career-threatening wrist injury, downed the 58th-ranked Polish player 6-4, 6-2 in blustery conditions on the Ken Rosewall Arena.

The 2009 US Open champion and Sydney top seed will take on unseeded Cypriot Marcos Baghdatis in Thursday's quarter-finals.

Baghdatis, the 2010 Sydney champion, took over two hours to subdue Australian Matthew Ebden 3-6, 7-5, 7-6 (7/3).

"It was really tough conditions today," del Potro said.

"I was just really focused on my serve in the first set, and then tried to take a little opportunity, because it was really difficult to play long rallies, to feel the ball like I wanted."

Del Potro only trails world number 10 Spaniard Nicolas Almagro by 65 rankings points and said it was his goal in 2012 to beat top-ten players after winning the ATP Comeback Player of the Year award, jumping from 257 to 11th.

Juan Martin del Potro won 6-4, 6-2

"I was really scared in this tournament last year because it was the first tournament after my (wrist) surgery," he said.

"But with time and practising I improved a lot and kept wining matches and that's helped me to keep the confidence to play healthy and play better.

"At this moment, I don't think of my wrist, so it's a good signal for the future."

Del Potro said winning a second grand slam was a big challenge for him.

"I think I'm still far (away) to do that goal, but I'm working. I'm feeling good every day," he said.

"So I need time and do it step-by-step and then be ready for that moment."

American second seed John Isner crashed out 3-6, 6-4, 6-3 to compatriot Bobby Reynolds, who will face Finland's Jarkko Nieminen in the last eight.

Nieminen, a runner-up here three years ago, accounted for eighth seed Radek Stepanek of the Czech Republic 7-6 (7/5), 5-7, 6-1.

French third seed Richard Gasquet cruised past Italian Fabio Fognini in straight sets and will take on Uzbekistan's Denis Istomin in the quarters.

Two more men's seeds were knocked out late Wednesday with Frenchman Julien Benneteau accounting for fourth-seeded Spaniard Feliciano Lopez 6-3, 6-4 and Russia's Alex Bogomolov Jnr eliminating Serbian fifth seed Viktor Troicki 7-6 (7/5), 6-4.

Benneteau and Bogomolov will fight out the last quarter-final match on Thursday.