One-day international, Headingley: Sri Lanka 324-2 beat England 321-7 by eight wickets
Sri Lankans Sanath Jayasuriya and Upul Tharanga produced a stand of 286, the third best in one-day internationals, as England lost the series 5-0.
Trescothick's century was soon overshadowed by later events
Sri Lanka won by eight wickets as Jayasuriya, in his last international on English soil, hit 152 off 99 balls and fellow opener Tharanga made 109.
England's score of 321-7 was passed in the 38th over, their bowlers unable to back up Marcus Trescothick's 121.
The day was overshadowed by the death of England bowling legend Fred Trueman.
The news came through in the 33rd over of the England innings and the home team, wearing black armbands, stood to pay tribute before Sri Lanka batted.
Earlier, while Trescothick was busy compiling his 12th century in one-day internationals, the crowd on a hot day in west Yorkshire would have been hoping for a rare England victory.
The Somerset left-hander made the most of a let-off on 36 - when he was given not out despite edging a catch to Kumar Sangakkara - to produce stands of 82 with Alastair Cook and 75 with Ian Bell.
Trescothick raised England's hundred in the 20th over with two effortless lofted boundaries off Dilhara Fernando.
The veteran Sanath Jayasuriya was in his element at Headingley
His century came up in the 33rd over but he could not stay until the finish, bowled six overs later by Jayasuriya as he attempted to make room to cut.
Vikram Solanki added an unbeaten 44 over the closing overs to ensure what was at that point the highest score of the series and the best in a Headingley one-day internationals.
Lasith Malinga was the pick of Sri Lanka's bowlers, using the yorker to great effect at the end of the innings to finish with 4-44 from his 10 overs.
In the context of such a high-scoring match, they were impressive figures indeed.
England's bowlers have been insipid throughout the series and, playing on Trueman's home ground, were uninspired by the passing of the great man.
With the pitch playing perfectly, Kabir Ali and Tim Bresnan were either too short, too full or too wide most of the time.
Jayasuriya and Tharanga needed no second invitation.
They flayed 133 off the first 10 overs, forcing Andrew Strauss to delay his powerplays, but even then they continued to tick the score along at a fast rate.
Jayasuriya, who gave Jamie Dalrymple a tough chance at backward point early in his innings, was typically forthright on the back foot through the off-side, but was able to indulge his entire repertoire.
TOP STANDS IN ODIs
331: R Dravid & S Tendulkar - India v NZ, Hyderabad '99
318: Dravid & S Ganguly - India v SL, Taunton '99
286: Jayasuriya & Tharanga - SL v Eng, Headingley '06
275: M Azharuddin & A Jadeja - Ind v Zim, Cuttack '98
There was further carnage when the 22nd over started, as Strauss finally did take the powerplay.
Steve Harmison was hit for three boundaries, and it was now only a question of how long Sri Lanka would take to win the match.
Finally, Tharanga gave Dalrymple a catch off his own bowling and Strauss cut Solanki to backward point, giving the Worcestershire man his first wicket in England colours.
In 2,388 previous one-day internationals, there had been only two bigger partnerships, both featuring current India captain Rahul Dravid.
Harmison bowled 10 overs for 97, officially the worst by an England bowler, beating Derek Pringle's "record" in 1987.
But he was only marginally more expensive than Dalrymple, and much less so than Ali and Bresnan, who bowled fewer overs.