Skipper Dimuth Karunaratne and Kusal Mendis hit gritty half-centuries on Saturday to lead a strong Sri Lankan reply on day two of the second Test against Australia.

The hosts reached 184 for two at stumps in Galle, where only a few spectators watched from the stands after a fresh outbreak of political unrest in the country.

Karunaratne made 86 in a marathon stand of 152 with Kusal before Mitchell Swepson broke through with the captain's wicket.

Kusal was still batting on 84 alongside Angelo Mathews, on six, at close of play, with Sri Lanka trailing Australia's first innings 364 by 180 runs.

Debutant Sri Lankan spinner Prabhat Jayasuriya claimed six wickets to bowl out Australia in the first session, with Steve Smith left unbeaten on 145.

The hosts were dealt an early blow when Mitchell Starc's pace bowling got Pathum Nissanka to edge the ball to gully, where Cameron Green took a good catch.

The left hand-right hand batting pair of Karunaratne and Kusal survived an inspired spell of pace bowling from Starc and skipper Pat Cummins to grind their way through the afternoon.

Karunaratne raised his fifty with a boundary off Swepson, while Kusal's stubborn resistance prompted Australia to rotate their bowlers.

Protests, unrest 

Premier off-spinner Nathan Lyon, who starred in the team's opening win with nine wickets, had 21 overs without success.

Swepson eventually trapped Karunaratne lbw on a delivery that skidded straight into the batsman's pads.

The tourists started the day on 298-5 with Smith, who scored his first Test hundred in 18 months on day one, resuming on his 109.

Jayasuriya, who took three wickets on the opening day, set a trap for overnight batsman Alex Carey, who miscued a reverse sweep to be caught at backward point for 28.

The left-arm spinner soon got Starc out for one to become the seventh Sri Lankan bowler to take five wickets in an innings on Test debut.

Jayasuriya was one of the three Sri Lankan players, along with Maheesh Theekshana and Kamindu Mendis, to be awarded a first Test cap following a Covid outbreak sidelining several members of the squad.

There were barely any spectators at Galle for the second day's play, with the host country embroiled in public unrest arising from its painful economic crisis. 

The morning session saw hundreds of protesters looking down on the Galle fort to demand the resignation of Sri Lanka's president -- who fled his home on Saturday shortly before a huge crowd of protesters stormed his residence. 

Australia lead the two-match series 1-0 after a crushing opening win inside three days during last week's first Test.

Sri Lanka v Australia second Test scoreboard

Scoreboard at the close of play on day two of the second Test between Sri Lanka and Australia in Galle on Saturday:

Australia 1st innings (overnight 298-5, Smith 109, Carey 16)

U. Khawaja b R. Mendis                      37

D. Warner b Rajitha                          5

M. Labuschagne st Dickwella b Jayasuriya   104

S. Smith not out                           145

T. Head b Jayasuriya                        12

C. Green lbw b Jayasuriya                    4

A. Carey c R. Mendis b Jayasuriya           28

M. Starc c K. Mendis b Jayasuriya            1

P. Cummins lbw b Rajitha                     5

N. Lyon lbw b Jayasuriya                     5

M. Swepson lbw b Theekshana                  3

Extras (b5, lb6, w1, nb3)                   15

Total (all out, 110 overs)                 364

Fall of wickets: 1-15 (Warner), 2-70 (Khawaja), 3-204 (Marnus Labuschagne), 4-238 (Head), 5-252 (Green), 6-329 (Carey), 7-333 (Starc), 8-338 (Cummins), 9-345 (Lyon), 10-364 (Swepson)

Bowling: Rajitha 25-4-70-2 (w1, nb3), R. Mendis 33-1-117-1, Theekshana 16-2-48-1, Jayasuriya 36-3-118-6

Sri Lanka 1st innings

P. Nissanka c Green b Starc                  6

D. Karunaratne lbw b Swepson                86

K. Mendis not out                           84

A. Mathews not out                           6

Extras (b1, w1)                              2

Total (2 wickets, 63 overs)                184