Lahiru Thirimanne carried his one-day international form into Sri Lanka's match against Northamptonshire as he and fellow centurion Kaushal Silva put their stamp on proceedings at Wantage Road.

Thirimanne, whose unbeaten half-century helped the tourists prevail in Tuesday's controversial Royal London Series decider against England at Edgbaston, had one significant piece of fortune in Sri Lanka's only warm-up match before next week's first Investec Test at Lord's.

The left-hander escaped a caught-behind chance first ball, Ben Duckett dropping the catch off Steven Crook, and went on to make 120 not out in an unbroken stand of 238 with opener Silva (152no).

Sri Lanka closed day one of four against an inexperienced Northamptonshire team, featuring two first-class debutants, on 358 for three.

The tourists took advantage, after Thirimanne won the toss, despite the early loss of Silva's opening partner Dimuth Karunaratne - splicing a catch to gully for just a single when Crook found some early bounce into the left-hander's body with the new ball.

Kumar Sangakkara then shared a half-century partnership with Silva but failed to cash in, hooking the occasional medium-pace of Kyle Coetzer straight to long-leg.

Coetzer, better known as a batsman for Northants and his native Scotland, had previously taken only four first-class wickets in 77 matches.

Crook also bagged a notable victim after lunch, Mahela Jayawardene falling four short of his 50 when Matt Spriegel pulled off a very good catch high to his left - at gully again.

The seamer then momentarily thought he had two in two, when Thirimanne edged behind.

Instead, there was to be no further success for the hosts - even with the second new ball - as Silva reached his century first off 186 balls and Thirimanne soon followed him at a slightly quicker tempo.