Dilshan, named Man of the Match and Man of the Series, emerged the unlikely bowling hero to rout Bangladesh for 158 after tea on the fourth day after helping his team set an improbable victory target of 624.

The 32-year-old followed his first innings 162 with 143 to become the fourth Sri Lankan to score a century in both innings of a Test as the visitors declared on 447 for six at lunch.

Dilshan then grabbed four for 10 as Sri Lanka wrapped up their biggest victory in terms of runs, surpassing the 315-run margin against Zimbabwe at Galle in January 2002.

It was also Bangladesh's heaviest defeat, having lost by 329 runs to England at the same venue in October 2003.

"We were in trouble at times but the guys showed a lot of fight and character especially Dilshan in the first innings when we were 75 for four," Sri Lanka captain Mahela Jayawardene said.

"That is something we encourage the boys to do as best they can."

Top scorer Shakib Al Hasan (46) was stumped by Prasanna Jayawardene to give Dilshan his first wicket and the spinner went on to mop up the Bangladesh tail.

RUN OUT

The innings ended when Mushfiqur Rahim (43) was run out 20 minutes before the scheduled close.

Leg-spinner Ajantha Mendis, who missed the 107-run first-Test win in Dhaka due to injury, picked up three for 57.

Earlier, Dilshan emulated compatriots Duleep Mendis, Asanka Gurusinha and Aravinda de Silva by hitting two centuries in the same Test.

Resuming on 296 for four, Sri Lanka lost their first wicket of the day when Thilan Samaraweera fell for 77.