Rafael Nadal has ensured he will finish the year ranked No.1 in the world after claiming back-to-back wins to begin his campaign at the season ending ATP finals. Nadal entered the London event knowing that two victories in his group would be enough to see off a challenge from Novak Djokovic, who had held the mantle for the best part of the past two years.

The Spaniard opened the tournament with a win over compatriot David Ferrer and followed up by beating Swiss seventh seed Stanislas Wawrinka in two tie-break sets. It is the third time Nadal ends the year as the world’s top player, having achieved the feat in 2008 and 2010, and caps a remarkable return to the summit of the men’s game since his comeback from injury.

“I had a lot of emotions today, it's the perfect scenario to be the year-end number one,” said Nadal. “After missing this tournament last year, it's been an unbelievable comeback.

“Being number one at the end of the season is something really difficult as there are some unbelievable competitors out there.”

The 27-year-old only started playing competitively again in February, having had seven months off with severe tendonitis in his knees. He claimed this year’s French and US Opens as well as eight other tournaments but has never won the Tour Finals event.

Nadal went into the match against the Swiss having won all of their eleven previous encounters – without dropping a set. However Wawrinka proved a more than worthy opponent and showed he could mix it with his counterpart, hitting twice as many winners throughout the contest.

Making his first appearance at the season ending event, the world No.8 was able to push Nadal to a tie-breaker in both sets. Unfortunately his unforced errors were a telling statistic and Nadal demonstrated his canny ability to pull out the big shots when it mattered to take the match and top spot.

Nadal’s win makes him the first player to end the year as world No.1 three years after last achieving the feat. It also means the Spaniard has booked a place in the semi-finals with one group match against Tomas Berdych still to be played.

“Stan played really great,” said Nadal after the match. “He had chances at the end and I was a bit lucky, but I'm happy to be through to the semi-finals in the last tournament of the year.”

Damien Bellemore