Stefanos Tsitsipas poses with the winner's trophy after winning the men's singles final match of the ATP World Tour Finals tennis tournament in London on November 17. Photo: Reuters

Greek star Stefanos Tsitsipas is eyeing a top-three finish next season as he hopes to break the rankings stranglehold of ­Rafael Nadal, Novak Djokovic and Roger Federer.

The 21-year-old concluded his 2019 season with a bang, lifting the ATP Finals crown in London on his debut in the tournament to end his year at No.6 in the world.

Tsitsipas toppled defending champion Alexander Zverev and 20-time Grand Slam winner Federer, en route to the final at the O2 Arena, before edging past Dominic Thiem in a three-set thriller.

Tsitsipas struggled to sleep in the days after his momentous victory. 

He says he kept getting flashbacks of the match point that earned him the biggest trophy of his young career.

"I'm currently living in the best period of my life, with the best people around me. I really feel like this is very important for my balance and for my thinking," Tsitsipas told reporters in Abu Dhabi, where he is contesting the Mubadala World Tennis Championship exhibition starting Thursday.

One of just two players to beat each member of the "Big Three" in 2019, Tsitsipas has set himself lofty goals for next season, as he looks to challenge Nadal, Federer and Djokovic at the majors.

The trio have 55 Grand Slam titles between them, and have won the last 12 consecutive majors. But with all of them aged 32 and over - Federer is 38 - Tsitsipas feels his generation will soon be able to knock the "Big Three" off their perches.

"I understand that our tennis era is changing in a way, the top-three are getting older obviously, we are the ones come from behind. So for me, I do have as a goal to win a Grand Slam title next year, that's for sure, but it's not a matter of life or death for me," explained Tsitsipas, who takes on Andrey Rublev in Abu Dhabi on ­Thursday, with the winner moving on to play Djokovic on Friday.

"One of my goals for next year would be a Grand Slam title, finishing in the top-three by the end of the year, making the Nitto Finals again and winning a Masters 1000."

He added, "We have Nadal, Djokovic, Federer, who are there, and have always been there. And what I need to do is go the extra mile and surpass them and that's going to be the biggest challenge for next year, I need to surpass one of them in order for me to finish in the top-three next year."

Tsitsipas' best Grand Slam result to date was reaching the semifinals of the Australian Open last January.