Kumar Sangakkara made a career-best 319 and joined the 11,000-run club on the way as Sri Lanka took firm control of the second Test against Bangladesh in Chittagong on Wednesday.
The tourists, who won the first Test by an innings and 248 runs in Dhaka last week, scored 587 in their first innings and Bangladesh replied with 86-1 by stumps on the second day.
Left-handed Sangakkara's maiden triple century was his ninth 200-plus knock, leaving him in second place behind Australian legend Don Bradman who had 12 scores of 200 or more.
Sangakkara, a 36-year-old veteran playing his 122nd Test, also became the ninth Test batsmen to reach the 11,000-run mark.
He now has 11,046 runs in the all-time list headed by India's Sachin Tendulkar (15,921).
"As a batsman, you always look at big scores," Sangakkara said. "There are 100s, 200s, 300s and Brian Lara has even got 400. Those are things you always try and chase when you have an opportunity.
"So I am very happy to have got into the 300-club at least."
The former captain said his next big aim was to help Sri Lanka play good Test cricket against the top sides.
"I have personally achieved quite a bit as a batsman, but the team's aim is to win a lot more Test matches, especially away from home," he said.
"Hopefully before I finish we will be able to beat some of the big countries in their own backyard. And keep playing really good Test cricket and keep improving."
Having started the day on 160, Sangakkara hit 32 boundaries and eight sixes before he was last man out before tea attempting to force the pace.
Bangladesh's reply began on the wrong foot when star opener Tamim Iqbal was bowled by Suranga Lakmal with the fourth ball of the innings.
But Shamsur Rahman (45 not out) and Imrul Kayes (36 not out) repaired the early damage by adding 86 for the unbroken second wicket.
Both batsmen were lucky to survive till close as Shamsur was dropped by Mahela Jayawardene on 36 and Nuwan Pradeep grassed a simple catch offered by Kayes just before stumps.
Bangladesh will still need to bat out a major part of the remaining three days to prevent a 2-0 series rout.
The day was lit up by glorious strokeplay from Sangakkara, who flayed Bangladesh's hapless bowlers on the slow pitch at the Zahur Ahmed Chowdhury stadium.
Left with number 11 Nuwan Pradeep at the other end, Sangakkara moved from 286 to 302 with a four and two sixes off consecutive deliveries from left-arm spinner Shakib Al Hasan.
Pradeep contributed just four in the 10th-wicket stand of 54 with Sangakkara, who knocked up 116 runs in the company of the last three batsmen.
Sri Lanka had begun the day on 314-5, and overnight batsman Kithuruwan Vithanage helped Sangakkara add 90 for the sixth wicket before the hosts hit back twice to make it 405-7.
Tail-ender Ajantha Mendis joined Sangakkara to add 100 for the eighth wicket before he was leg-before to Shakib for a fluent 47.
Shakib finished as Bangladesh's most successful bowler with five wickets, but his 34 overs cost 148 runs.
The hosts were dealt a double blow before play began as skipper Mushfiqur Rahim was unable to take the field due to a finger injury and spinner Abdur Razzak was sidelined with a strained hamstring.
Tamim Iqbal led Bangladesh in Rahim's absence and Shamsur kept wicket.
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