Just days after they'd been shot out for 67 at Old Trafford, Sri Lanka made 300 for nine after being sent into bat.
Sangakkara's 112 -- his first hundred at Lord's in any format -- was the centrepiece and together with Tillakaratne Dilshan (71), he put on 172 for the second wicket.
The duo had managed just 15 runs between them during the course of a 10-wicket defeat in Manchester on Wednesday that left England 2-1 up in the five-match series.
This innings also represented a reversal of fortune for England paceman Chris Jordan, who took a career best five for 29 at Old Trafford.
But his 10 overs, including eight wides, on a typically good Lord's pitch cost 67 runs as he struggled to bowl the correct length.
And Jordan's two wickets Saturday only came during his final over as Sri Lanka hit out.
Sangakkara's 19th ODI century had an unpromising start as the 36-year-old took 13 balls to get off the mark.
But such was the composure and experience of the left-hander, playing his