Rafael Nadal of Spain poses with his ATP World No. 1 trophy following the singles group match against Stefanos Tsitsipas of Greece at the ATP World Tour Finals 2019 in London, Britain on Nov. 15, 2019. (Xinhua/Han Yan)

LONDON, Nov. 15 (Xinhua) -- World number one Rafael Nadal took two hours and 52 minutes to outpass Greek hopeful Stefanos Tsisipas 6-7(4), 6-4 and 7-5 here on Friday, but still need to wait the result of the evening match for taking a semifinal berth at the ATP World Tour Finals.

The 21-year-old debutant Tsitsipas has already qualified for the semifinals after winning the previous two group matches on fire, while Nadal will definitely go home if he loses the last round group match.

The Spaniard lost the tiebreak 7-4 in first set but broke in the ninth game in the following set. The 33-year-old created several chances to break in the deciding set, then finally made it in the 11th game.

However, Nadal has to count on Daniil Medvedev for keep going. He can advance into the semifinals only if the Russian world number four beats German defending champion Alexander Zverev in the night session.

Nadal has secured the year-ending world number one ranking after Roger Federer ousted world number two Novak Djokovic last night in the other group.