Argentina's Juan Martin del Potro crushed Serbian eighth seed Janko Tipsarevic 6-0, 6-4 on Thursday to keep alive his hopes of securing a place in the semi-finals of the ATP Tour Finals.
After both players lost their opening Group B matches, this clash at London's O2 Arena had become a must-win encounter and it was former US Open champion del Potro who seized his chance to avoid an early exit with a brutal display of power hitting.
Del Potro, seeded sixth, has lost just twice indoors in 2012 and he blew Tipsarevic off the court in just one hour and 16 minutes.
The Argentine still needs a win against Roger Federer in his final group match on Saturday to reach the last four and even that may not be enough depending on the result of David Ferrer's meeting with Tipsarevic.
At least del Potro still has a chance, unlike Tipsarevic who is destined to crash out after losing both his matches without even winning a set.
"I'm so glad to be part of this amazing tournament. I'm trying to play my best tennis," Del Potro said.
"It's not easy to win a set 6-0. Janko was fighting. He's a very good player.
"I have a high step up against Federer on Saturday but I will try to beat him.
"I have worked a lot every day to be here after my injury problems. I'm back in the top 10 and I really want to enjoy this week."
Only Federer, Novak Djokovic and Ferrer have amassed more than del Potro's career-high total of 65 match wins this year and, with recent titles in Basle and Vienna on his CV, he is clearly determined to finish the year on a high.
Del Potro, who was Tour Finals runner-up in 2009, had won all three of his previous encounters with Tipsarevic and the result was never in doubt after he made the perfect start with a break in the opening game.
The Argentine saved a break point on his own serve before seizing control of the set with a second break, secured with a forehand bludgeoned with ferocious power.
Leading 3-0, del Potro refused to take his foot off the gas and he broke again in the fifth game before closing out the set.
Tipsarevic had been struggling with a virus before the start of the tournament and he looked short of energy and inspiration here.
He finally stopped the rot by holding serve at the start of the second set, but del Potro was striking the ball too well to be denied for long and he landed the decisive break in the fifth game.