Relentless pressure, meticulous planning and near-perfect execution from the bowlers have put Sri Lanka in the driving seat against Bangladesh three days into the ongoing Chattogram Test, making the hosts look completely out of depth in comparison.

Bangladesh got skittled out for a mere 178 in their first innings in reply to Sri Lanka's mammoth 531 -- their fifth straight total of less than 200 in Tests.

Resuming the day's play on 55-1, overnight batters Zakir Hasan and Taijul Islam had done well to survive the first hour, however, the Sri Lankan bowlers did not get bogged down, remained vigilant and soon got their rewards.

Both overnight batters and skipper Najmul Hossain Shanto departed in the second hour of the session and after lunch, the visitors claimed the remaining six wickets to secure a massive 353-run lead.

Sri Lankan pace trio led by Asitha Fernando, who took 4-34, claimed eight of the 10 wickets that fell on the day. Their pace bowling coach Dharshana Gamage was mighty pleased with the efforts of his pacers and said how tireless discipline was the key behind this performance.

"In Test cricket we always plan around keeping our discipline. Before even planning for the batters, we focused on keeping discipline in the bowling, how to set a field and bowl according to that consistently," Ghamage said at a press conference after the day's play.

Sri Lanka had specific game plan and field sets for each of Bangladesh's batters and at the press conference, Gamage revealed how they successfully planned the dismissal of Shakib Al Hasan, who was trapped lbw for 15 by Asitha.

"Asitha is someone that can bowl well with both the new and old balls. When it came to Shakib, the plan was to bowl a few short ones to push him back and then go fuller and trap him, and he did just exactly that.

"Normally before the match we have the bowlers meeting, so we have different field sets for each batter. [Captain] Dhananjaya [de Silva] set those fields well in the middle overs."

Compared to the planned approach from Sri Lanka, who played with almost the same intensity throughout the match, the Bangladesh players were guilty of letting the match situation affect their intensity, something Zakir inadvertently admitted to while explaining why the entire slip cordon chased after a ball to the third-man boundary.

"When you get wickets, these efforts automatically come out. We are trying to hold onto that level of effort all the time. In that situation, everyone was putting extra efforts and tried to chase the ball," the left-handed batter said.

Sri Lanka are now leading by 455 with four wickets in hand and Gamage said they hope to bat one more session, leaving their bowlers five sessions to bowl Bangladesh out. "We have 450-odd-run lead, so 50 more and we can get a lead of 500. If we bat the first session, then we have five more sessions to bowl at them."