Tunisia's Ahmed Jaouadi added the 1 500m freestyle world title to his 800m crown on Sunday for a Singapore double, with two-time Olympic champion Bobby Finke only third.

Jaouadi won a thriller to grab gold in 14min 34.41sec, ahead of Germany's Sven Schwarz (14:35.69) and the American world record holder Finke (14:36.60).

With three laps to go in the gruelling long-distance race, it was a three-way tussle between Jaouadi, Schwarz and Finke.

Jaouadi timed it to perfection, leading at the bell from the German and holding him off in the final lap.

"A lot of pain, a lot of struggle. I knew that everyone is struggling and everyone is feeling the pain," said the Tunisian.

"I wasn't the only one. I just tried to be the strongest one mentally. It was a good one because all of the boys swum a good race and everyone tried to win it.

"Through my body it was a lot of pain, it hurts. But through my mind was I want this medal, I want to win it. It's as simple as that."

Jaouadi's 800m free title earlier in the week was his first major crown.

Finke is the two-time reigning Olympic champion in the 1 500m and world record holder following his 14:30.67 in Paris a year ago.

Jaouadi was sixth in the French capital.