Sam Robson scored his second century of the tour as England Lions reached 291-4 in reply to Sri Lanka A's 289 on day two of four in Dambulla.
Middlesex right-hander Robson hit 17 fours in his 255-ball innings and put on 197 for the third wicket with James Taylor, who was 99 not out at the close.
Robson's opening partner Alex Lees was caught behind for 11 off Lahiru Gamage's bowling in the fourth over of the Lions' reply.
Gamage (2-59) also accounted for Varun Chopra (28) before Robson and Taylor produced a partnership spanning 50 overs to move the tourists into a strong position.
Robson, born in Australia but eligible and committed to representing England in international cricket, continued his impressive form this winter.
He scored two hundreds for the England Performance Programme in Australia before Christmas and also reached three figures against the Sri Lanka A Emerging Players in Colombo three weeks ago.
Spinner Tharindu Kaushal eventually removed Robson for 142, his 10th first-class hundred, and also bowled Ollie Rayner (1) in his next over.
But Taylor, who has hit 13 fours and faced 147 deliveries so far, remained resolute through to stumps alongside Jonny Bairstow (0no).
At the start of the day, Sri Lanka A added eight runs to their overnight position of 281-9 before Liam Plunkett (2-37) took the final wicket in the third over.
England's second-string Lions won the first of three unofficial four-day 'Tests' between the sides last week in Pallekele by 167 runs.