The overnight pair put on 119 for the sixth wicket as Sri Lanka, chasing an improbable target of 379 to win on a crumbling wicket, moved to 187-5 by lunch at the Galle International Stadium.

Jayawardene, 34, was unbeaten on 90 with the help of 15 boundaries and a six and looked on course for his 29th Test century.

Mathews, 10 years younger than his partner, showed why he is regarded as one of the most exciting young talents in the modern game as he chipped in with 66 not out.

The partnership made amends for the home team's poor batting earlier in the match, when Sri Lanka were shot out for 105 in the first innings and reduced to 68-5 in the second.

But Australia continue to hold the edge as they press for victory in the opening encounter of the three-Test series, their first in Sri Lanka since 2004.

Sri Lanka had added six runs to their overnight score of 120-5 when heavy rain interrupted play for an hour.

But the weather cleared soon and the umpires delayed the lunch break by 30 minutes to make up for lost time.

Australian captain Michael Clarke rotated his four frontline bowlers in a bid to break the stand as Jayawardene and Mathews dug in to keep the scoreboard moving.

Mathews reached his third half-century with two consecutive boundaries off Mitchell Johnson, guiding the left-arm seamer through third man before pulling him to the mid-wicket fence.

A confident Jayawardene lofted off-spinner Nathan Lyon for six and then played an audacious scoop shot off the same bowler over the wicket-keeper's head, a stroke made famous by his captain Tillakaratne Dilshan.

The second Test will be played in Pallekele from September 8 and the third at the Sinhalese Sports Club in Colombo from Sept 16.