Rafael Nadal may not have won his match with Dominic Thiem at the ATP Finals on Tuesday, but he probably won rally of the tournament.
Thiem produced a fearless display of attacking tennis to beat Nadal 7-6 (9-7) 7-6 (7-4) in a high-quality duel and seize control of their group.
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World No.3 Thiem saved a couple of set points in the first tiebreak before whipping away a forehand to take an opening set in which there was barely anything between the two.
Spaniard Nadal, bidding to win the only big title to elude him, engineered the first break of the match at 3-3 in the second set only for Thiem to reply in stunning fashion.
Nadal was on the brink of defeat when he slipped 0-40 behind serving at 4-5 after a wayward smash, but the 20-time grand slam champion dug himself out of a hole, saving three match points.
The World No.2 produced an insane tweener to stay alive on game point, showing incredible skills to recover and level the match at 5-5.
The remarkable rally sent tennis fans into a frenzy.
Thiem beats Nadal in epic encounter
However US Open champion Thiem was unshakeable and forged his way into a 6-3 lead in the day’s second tiebreak.
Nadal clawed one point back, but Thiem finished it off when his opponent dragged a backhand wide, a rare unforced error in an absorbing contest sadly played out in an empty O2 Arena.
Thiem had downed reigning champion Stefanos Tsitsipas of Greece in his opening round-robin match in the London Group and will qualify for the semi-finals if Tsitsipas beats Russian debutant Andrey Rublev later.
World No.2 Nadal's fate will rest on his final group match against Tsitsipas.
“It was a great match from the first to the last point,” Thiem, now well-and-truly established as a major force in the men's game, said after his sixth career win over Nadal in their 15 meetings and third in the last four.
“Actually I was a bit lucky to get the first set, I was 2-5 down in the tiebreak and against Rafa it's nice to win the first set.
“It's tough times for everyone at the moment and I hope we put on a good show for people watching on TV.”
The quality of the rallies in the first set would have graced a final in front of a sell-out crowd with neither player taking a backward step.
Heading into the tiebreak both had won 34 points each, with hardly a free gift in sight.
So it was a surprise to see a couple of errors from both men in the breaker.
Nadal served a double-fault and Thiem, after battling back from 2-5 to 5-5, then threw in one of his own.
Nadal netted a routine backhand on his first set point but was powerless as Thiem saved another with a grasping forehand.
When Thiem's chance arrived he was ruthless, again clubbing a forehand out of Nadal's reach.
The rallies were unrelenting in the second set and when Nadal saved the match points in the 10th game it looked likely the match would swing his way.
But Thiem, 27, had other ideas.
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