Angelo Mathews hailed "special" talent Kusal Mendis and brilliant "old man" Rangana Herath after Sri Lanka sealed a remarkable 106-run victory over Australia in the first Test on Saturday.

Sri Lanka looked destined for another defeat when they were skittled out for only 117 on day one in Pallekele, but turned things around to secure only their second Test win against Australia.

Man of the match Mendis dragged Sri Lanka back into the opening game of the three-match series with a magnificent 176, his maiden Test century at the age of 21.

Australia, the top-ranked side in Test cricket, started day five on 83-3, needing another 185 runs for victory, and were bowled out for 161 following a half-century from Steve Smith (55) as well as a defiant stand from Peter Nevill (9) and the injured Steve O'Keefe (4).

Veteran left-arm spinner Herath took 5-54 to add to his four first-innings wickets, while debutant Lakshan Sandakan (3-49) ended up with seven scalps in the match to ensure Sri Lanka pulled off a famous win.

Sri Lanka captain Mathews said: "I don't have words to explain [his emotions] after a very hard few months.

"We regrouped, trained really well and prepared to the best. Brilliant effort by the whole team. Credit to the Australians, they bowled really well. It was not a good effort by our batters in the first innings, we needed that 200-plus lead.

"It was a special knock by a special young player [Mendis], fantastic effort. The old man Herath was brilliant once again. Sandakan is a brilliant find for us.

"We knew this was going to take our turn, Sandakan responded brilliantly."