It may seem an absurd thing to say, but for a while Novak Djokovic was in danger of becoming 2013's forgotten man.
He may have started the year as the world's number one player, but Rafael Nadal's miraculous return from a knee injury, accompanied by Andy Murray's first Wimbledon title and the once all-conquering Roger Federer's decline, threatened to remove Djokovic from the forefront of people's thinking.
He would, though, go on to produce a strong reminder as the season drew to a close.
Having lost in the final of the US Open to Murray in September 2012, the Serb was provided with an almost immediate opportunity to gain revenge at January's US Open in Melbourne.
The Brit took the first set on a tie-break, but Djokovic responded by claiming the second in similar fashion, before going on to win his sixth Grand Slam title by dropping just five games in the next two sets.
The Dubai Tennis Championships soon followed, but his 22-match unbeaten streak was ended at the semi-finals of Indian Wells in March by Juan Martin del Potro.
Arguably one of Djokovic's most impressive feats of the campaign was achieved in April when he toppled the 'King of Clay' Nadal at the Monte Carlo Masters. The Spaniard had won eight successive tournaments in the principality - a run that stretched back 46 matches - but he was defeated 6-2 7-6.
It failed to inspire further success on the red stuff, though. He was knocked out early in Madrid and Rome by Grigor Dimitrov and Tomas Berdych respectively, before eventual champion Nadal came out on top in the semi-finals of the French Open at Roland Garros.
The final of Wimbledon in July pitted Djokovic against home favourite Murray, who would go on to end Britain's 77-year wait for a male singles champion at SW19. He was just too good for Djokovic on the day, coming out on top 6-4 7-5 6-4.
With the hard court segment of the campaign now underway, Djokovic looked on as Nadal won the ATP 1000 Masters title events in both Montreal and Cincinnati.
Rafa took that form into the US Open, which would prove too much for Djokovic, who would become a losing finalist at Flushing Meadows for the second year in succession.
No doubt wounded by some big-match defeats, Djokovic retaliated on the Asian leg of the season, scooping the titles in Beijing and Shanghai in the process. Nadal would continue to be a thorn, though, as he regained top spot in the world rankings.
Even with a win at last month's Paris Masters under his belt, Djokovic went into the season-ending ATP World Tour Finals as the second seed. Even so, he made light work of a group that included Federer, Del Potro and Richard Gasquet, winning all three matches.
Stanislas Wawrinka was then brushed to one side in the semis and he was once again paired him with Nadal. The man from the Balearic Islands may have secured his spot as the world's number one player for the year, but Djokovic sent out a message of intent for 2014 by retaining the title with a 6-3 6-4 success at London's O2 Arena.