Tsitsipas keeps hopes of qualifying for the ATP Finals alive with gritty win in Paris

The Greek, ranked 11th in the world, is in contention for a place in the Turin showpiece, which runs from November 10th-17th, although there are other better-placed rivals still involved in Paris.

He, Alex de Minaur of Australia and veteran Bulgarian Grigor Dimitrov all still aspire to take one of the three places still up for grabs.

Novak Djokovic (sixth), Andrey Rublev (seventh), Casper Ruud (eighth) currently occupy the final three spots but are either not competing in Paris or have already been knocked out.

"Starting the second set, I felt like a bull," said Tsitsipas who likely needs a run to the Paris final to stay in contention for Turin.

"I was ready to fight until my last breath on the court."

For a time it seemed Tsitsipas would also be leaving Paris prematurely as Cerundolo swept through the first set tie-break.

However, Tsitsipas, who beat Cerundolo on their only previous meeting in Basel earlier this month, broke the Argentinian in the third game of the second set.

He held onto the break and levelled the match by taking the set 6-4 on his fourth set point.

Tsitsipas then had the upper hand in the decider, cruising through to win it 6-2.

He will face world number three Alexander Zverev, who later beat France's Arthur Fils, for a place in the semi-finals.