LONDON, Nov 9 (Reuters) - Argentina's Juan Martin del Potro found himself in a strangely familiar position at the ATP World Tour Finals on Thursday after keeping his hopes on track with victory over Janko Tipsarevic.
Del Potro was in impressive form as he overpowered the Serbian world number nine 6-0 6-4 in his second Group B match at the season-ending tournament and now goes into his last round-robin match needing to beat Roger Federer to give himself a chance of reaching the semi-finals.
It is a similar scenario in 2009 when he also faced the Swiss in his third match needing to win. Then he pulled off a three-set victory that saw him squeeze through at the expense of Britain's Andy Murray by virtue of a games countback.
That night three years ago was also memorable for the fact that Del Potro knocked around on court with soccer player Carlos Tevez while the ATP did the calculations to work out whether he or Murray had qualified for the semi-finals.
It could be equally complicated on Saturday when he faces the defending champion who is already assured a place in the last four having won both his matches comfortably.
Del Potro will be hoping Tipsarevic can do him a favour by upsetting Spaniard David Ferrer although the man dubbed the Tower of Tandil knows he will have to repeat the form he showed when beating Federer in Basel last month to give himself a chance of emulating his run to the final three years ago.
"Well, first I'm glad to beat Janko tonight," said Del Potro, who arrived in London with 63 match wins this year thanks to a return to the destructive tennis that captured the 2009 U.S. Open and fired him to the final in London.
"To win in two sets give me a chance to go to the next round. But before I need to beat Roger once again, it's going to be a different match like 2009 here, but also is going to be a special match for me.
"It could be my last match in this season, so I will try to play similar to the Basel final, trying to be more aggressive than him all the time and see if I have a little chance."
Del Potro, at 24 the youngest of the eight qualifiers for the sell-out events at the O2 Arena, was too good for Tipsarevic on Thursday, his booming forehand causing havoc.
He only faced one break point and was totally dominant, although he acknowledged beating Federer would require another step up in performance.
"I'm glad with my level at this moment. But I know if I want to beat Roger, I should play much better than today and my first match," added del Potro, who was beaten by Ferrer on Tuesday.
While Tevez provided a hitting partner three years ago, on Thursday it was another Manchester City soccer and compatriot Sergio Aguero who knocked up on court with del Potro after Tipsarevic had been dispatched to the locker room.
So how was Aguero's tennis, del Potro was asked.
"He's a good soccer player," was the diplomatic reply. (Editing by Greg Stutchbury)