Usain Bolt may have won three world titles but after securing victory in his final race of the year he said 2013 had not been his best season.
Bolt won the 100m at the Diamond League finale in Brussels in 9.80 seconds, ahead of Mike Rodgers of the United States (9.90) and fellow Jamaican Nesta Carter (9.94).
"I got injured at the start so it was not the perfect season or the best of my career," he told BBC Sport.
"The best thing is I finished on top."
Diamond League 2013 Usain Bolt cruises to Brussels
The 27-year-old was again slow out of the blocks in Brussels, but powered past his rivals in the last 40 metres to win.
"My start felt better but I need to work on it. I can definitely run faster," added Bolt who won the 100m, 200m and 4x100m titles at August's World Championships in Moscow.
Briton James Dasaolu, the second fastest Briton ever after recording 9.91 seconds this season, finished eighth on Friday night.
"For me it was about executing the start and I didn't do that as well as I would've liked to," the 26-year-old world 100m finalist told BBC Sport.
"I gave it my best, but maybe I was a bit distracted. When you look at my goals for the season I wanted to run sub-10 seconds, which I have done twice, and I made the final in Russia."
There was success for Jamaican athletes elsewhere, with triple world champion Shelly-Ann Fraser-Pryce winning the women's 100m in an impressive 10.72 seconds - just one hundredth of a second slower than the fastest time of the year, set by the sprinter at the Moscow championships.
Victory sealed the Diamond Race - won by those who have accumulated the most points in their respective event during the Diamond League season - for the Jamaican and the $40,000 (£25,591) first prize that goes with it.
Compatriot Warren Weir secured the men's the 200m Diamond Race with victory in a time of 19.87 seconds.