A stunning maiden Test century from 21-year-old Kusal Mendis has almost single-handedly lifted Sri Lanka out of a huge hole and given them the ascendancy over Australia in the first Test in Kandy.

When bad light stopped the third day’s play early at Pallekele Stadium, Sri Lanka were 6-282 in their second innings, earning them a 196-run lead in a formidable turnaround after being blasted out on day one for just 117.

Sri Lanka were in strife at 2-6 when Mendis walked out at No.4: 22 wickets had fallen in four sessions, the pitch was still a bit inconsistent in bounce and pace, he’d only made eight in the first innings, they were still 80 runs behind Australia and the tourists’ well-balanced attack was ready to go in for the kill.

Oh, and Mendis had only one first-class century to his name.

Mendis celebrates his stunning century. Photo: AP

Undaunted, the jockey-sized Mendis took on the Australian bowlers, cutting and driving the fast bowlers and sweeping the spinners in a brilliant knock of 169 not out, Dilruwan Perera is at the crease with him, unbeaten on 5.

Mendis wasn’t without luck, but his timing in scoring his first Test ton in only his seventh Test was impeccable.

With bravado befitting his age, Mendis brought up three figures with a slog-sweep for six over deep midwicket.

His score is easily the highest of the match thus far, with the next best being Adam Voges’ 47 in Australia’s total of 203.

It surpassed Mendis’ previous best of 53 at Test level and he’s well on track to make the highest score by a Sri Lankan against Australia, a record held by Kumar Sangakkara when he belted 192 in Hobart, in 2007.

Aside from trying to find a way to extract Mendis, Australia have another major concern.

Left-arm spinner Stephen O’Keefe left the field with a right hamstring complaint midway through the second session.

Cricket Australia said they are assessing the injury, but it will be a big blow to the tourists if he’s ruled out for the rest of the innings, given the wicket is taking plenty of turn and O’Keefe (1-42) had been creating a number of chances.

Mendis’ 117-run partnership with Dinesh Chandimal (42) set the platform for Sri Lanka’s revival.

He also added 71 with debutant Dhananjaya de Silva (36).

Nathan Lyon is mobbed after dismissing Sri Lanka’s Dhananjaya de Silva. Photo: AP

Of the 15 Sri Lankan wickets to fall so far, eight have been lbw.

After Australia required only four bowlers and 34.2 overs in the first dig, skipper Steve Smith used eight – including himself, David Warner and Adam Voges – on Thursday as he looked for answers against Mendis.

Mitchell Starc bowled at good pace and with a bit of reverse swing in taking 2-44.

Nathan Lyon (2-98) got through 26 overs with O’Keefe injured and was typically accurate and threatening in taking the big wicket of skipper Angelo Mathews.

-AAP