Just nine runs behind the Tigers' first-innings total on 504 for three with two set batsmen in Roshen Silva and skipper Dinesh Chandimal at the crease after the third day, Sri Lanka are in prime position to take control of the first Test and stretch their lead today at the Zahur Ahmed Chowdhury Stadium in Chittagong.

Much like on the previous day the Bangladesh bowlers remained helpless, repeating the same mistakes and not getting any purchase from the pitch that had very little to offer since Sri Lanka resumed the third day on 187 for one.

Regardless of Bangladesh's shortcomings and the wicket, the two overnight Sri Lanka batsmen Dhananjaya de Silva and Kusal Mendis deserve most of the credit as both right-handers fully utilised the opportunity.

Mendis, however, was lucky for the third time -- and Mustafizur Rahman was the aggrieved bowler for the second time -- after getting lives on four and 57 on the second day. Batting on 87 in the third over yesterday, the right-hander edged a back-of-a-length delivery from the left-arm seamer but it went between first and second slip.

From that point, Mendis and De Silva went on the charge and added 108 runs in the first session without losing a wicket, in the process reaching a few milestones.

Birthday boy Mendis, who resumed the day on 83, went on to register his fourth Test hundred in style with a boundary off left-arm spinner Sunzamul Islam, having faced exactly 200 balls. De Silva, having reached his fourth century the previous day, started cautiously before opening up and reached 150 off his 187th delivery. When he reached 157 he became the joint-fastest Sri Lanka batsman -- along with Roy Dias and Michael Vandort -- to score 1,000 runs.

Bangladesh finally got the breakthrough as Mahmudullah took the new ball after lunch and it was Mustafizur who got his deserved reward when he dismissed De Silva for a career-high 173.

The 26-year-old went for a pull off a rising Mustafizur delivery that was angled away but the right-hander only managed to get a leading edge for wicketkeeper Liton Das to run across to short cover and pouch safely.

Mendis at the other end shifted gears but was lucky yet again -- this time it was a run-out opportunity -- when he and Roshen Silva were stranded in the middle of the pitch but Mehedi Hasan Miraz's throw flew over the keeper's head.

Later, Mendis went past his previous best of 194 that also came against Bangladesh last year in Galle, and was eyeing his maiden double ton. However, the right-hander who has a tendency to charge the bowlers just before a break paid the price when he came down the track to hit left-arm spinner Taijul Islam over midwicket but only managed to get a leading edge. Mushfiqur Rahim took a fantastic catch running backwards to end a superb knock of 196 off 327 balls that featured 22 fours and two sixes.

Meanwhile, the Tigers continued making mistakes. Silva was on one when wicketkeeper Liton was unable to hold on to the ball and missed a stumping chance down the leg side off the bowling of Mehedi in the 86th over.

The missed opportunity proved costly yet again as Silva and Chandimal watchfully played out the final session, during which the bowlers managed to keep things tight and limited the Lankans to 88 runs.

Silva capitalised on the opportunity and was eyeing his maiden hundred in just his second game. He will resume the fourth day on 87 while skipper Chandimal paused his innings on a 90-ball 37 and is set to add to the 89-run fourth wicket stand today.