After resuming on 3-504, the visitors added 109 runs in the first session to surpass 600 and eclipse England's 6 (dec)-599 against Bangladesh in 2010 for the highest innings total at the venue.
Chandimal returned to the pavilion scoring 87 runs, but before that, he ensured that his team has taken more than 100-run lead in first innings.
Sensex stumbles 250 points but stays above 36000-mark
The 30-share BSE Sensex was 164 points down at 36,119 while the broader NSE Nifty was 64 points down at 11,066 in opening trade. In the Asian region, Japan's Nikkei was up 0.50 percent, while Hong Kng's Hang Seng fell 0.24 percent in early deals.
Sri Lanka's Roshen Silva has scored a maiden century on day four of the first Test with Bangladesh. "If our batsmen can survive the fifth day, then we can get something out of it. Batsmen would like to score runs off the bad balls". De Silva also completed his 1,000 Test runs and became the joint-fastest Sri Lankan to do so, along with Roy Dias, taking 23 innings only. The fact that it stayed low did the batsman in who got a bottom edge that was pouched by Liton Das. Mendis' role was more of an anchor as de Silva looked destructive throughout his innings, hitting 21 fours and a six so far.
Dilruwan Perera (1-20) dented Bangladesh's momentum when he had Kayes caught at square leg while Lakshan Sandakan (1-3) in his first over had Tamim caught behind.
Dickwella signalled his intention with three successive fours off Taijul, who did enjoy some respite in cleaning up Chandimal three balls after the lunch break.
Sri Lanka wicketkeeper Niroshan Dickwella later said that despite the batting-friendly Chittagong pitch, it is their game to win.