No defending champion has lost his first two matches at the Nitto ATP Finals since 2006, and Stefanos Tsitsipas refused to snap that streak Tuesday evening.

The Greek saved a match point to defeat tournament debutant Andrey Rublev 6-1, 4-6, 7-6(6), guaranteeing Dominic Thiem’s place in the semi-finals of the season finale. The Austrian has a 2-0 record in Group London 2020 and is the first player to earn a spot in the last four at The O2.

Tsitsipas played a tough three-setter against Thiem on Sunday, with only a few points making the difference. The same was the case against Rublev. But this time, it was even closer for the 22-year-old. Rublev won four consecutive points from 5/2 down in the final-set tie-break to earn match point. The Russian double faulted, though, and Tsitsipas took full advantage.

The reigning titlist held his nerve under pressure, making fewer errors in the key moments to outlast the Russian after one hour and 55 minutes. He hit crucial inside-out forehand at 6/6 to earn the decisive mini-break, levelling his record in round-robin action at 1-1.

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The pair walked on Centre Court level at 2-2 in their ATP Head2Head series, and once Rublev found his rhythm, their level was mostly even for the rest of the match. But for a while, it appeared Tsitsipas was in cruise control.

The 2018 Next Gen ATP Finals champion needed just shy of 20 minutes to breeze through the first set, dominating with his serve and preventing the tournament debutant from gaining any rhythm.

Rublev immediately lost serve by missing a straightforward two-handed backhand and seemed to be struggling to cut down his mistakes, much like he did against Rafael Nadal on Sunday. But the Russian succeeded in putting the first set behind him, and from there the quality from both men was high on Centre Court.

One of the keys for the seventh seed was digging his teeth into points. The seventh seed was frustrated with the number of returns he was missing in the opener, especially on the forehand side. But he simultaneously cut down his errors and increased his aggression once he was able to land more returns, and that proved critical in turning the tide.

Tsitsipas did not face a break point in his first eight service games of the match, but he played a sloppy game at 4-5 in the second set to give Rublev confidence. The Russian took full advantage, pummeling a forehand to break at love and force a deciding set.

Neither man was able to pull away, and they both played clutch service points under pressure to move into a tie-break. Tsitsipas swooped into net for a backhand volley, which gave him a 5/2 advantage. But Rublev refused to give up, fighting back to earn match point. He was unable to finish the job.

Rublev has been eliminated from semi-final contention at The O2. He will try to earn his first win at the season finale against Thiem.

Source: Tennis – ATP World Tour