Entering Wednesday's showdown, Rafael Nadal and Daniil Medvedev found themselves in an unexpected position after losing their ATP Finals openers.
Needing a win to bolster their title hopes, their US Open final replay delivered plenty of intrigue, as Nadal survived a match point to edge the Russian, 6-7 (3), 6-3, 7-6 (4). Nadal will now finish as the year-end No. 1 unless Novak Djokovic wins the title at The O2.
Here are the Top 5 photos from the pair's round-robin meeting in London. (All by Getty Images)
The first set featured zero breaks, but Medvedev was more efficient on serve. It ultimately paid dividends in securing the tiebreaker.
Nadal put the deficit behind him, finding his range with an 11% increase in his first serve percentage to emerge as the stronger player in set two.
Medvedev blasted out the gates to take a commanding lead in the third set, reaching match point with Nadal serving down, 5-1, 40-30.
Nadal dug in with each game and suddenly leveled the set, as Medvedev failed to reach match point in his two service games.
From 3-4 in the decisive tiebreaker, Nadal claimed the final four points to prevail in two hours and 46 minutes. Medvedev suffered his third consecutive defeat and will be eliminated from contention if Alexander Zverev defeats Stefanos Tsitsipas.