Sri Lanka captain Dhanajaya de Silva said Kamindu Mendis had significantly strengthened his team's middle-order batting following their 2-0 series sweep of New Zealand on Sunday.
Kamindu made the fifth century of his fledgling career on Friday with an unbeaten 182, allowing Sri Lanka to declare their first innings on 602-5 and set up an innings victory in the second test.
Promoted to No 3, Dinesh Chandimal also struck a century in further vindication of the team's decision to rejig their batting order.
"I think Kamindu at five can play the long innings and I can finish the game at No 6," De Silva said.
Kamindu, who made a hundred in the opening test, became the fastest Asian to 1 000 test runs by reaching the milestone in his 13th innings.
"I'm enjoying scoring runs, specially since Galle is my home town," Kamindu said after collecting player-of-the-match award.
"It is a great pleasure to score 1 000 runs so quickly, but we have to improve day by day."
New Zealand captain Tim Southee said playing two tests at Galle, known as a spinner's paradise, was always going to be challenging.
"It's a tough place to come for a foreign team, and Sri Lanka played some great cricket," Southee said after New Zealand slipped to seventh place in the World Test Championship (WTC) standings.
New Zealand were effectively out of the game after being dismissed for 88 in reply to Sri Lanka's mammoth first-innings total.
They managed an improved showing – 360 all out – in the second innings with half-centuries from Devon Conway, Tom Blundell, Glenn Phillips and Mitchell Santner but could not avert their biggest loss against Sri Lanka.
New Zealand head to India for a three-test series beginning on October 16.