(Reuters) - Opener Dimuth Karunaratne stayed on course for his third test century as Sri Lanka lost one more wicket in the second session to reach 141 for two at tea on the opening day of the first test against West Indies on Wednesday.

On a pitch offering little assistance to their pace battery, West Indies did not help their cause by spilling two catches after lunch at the Galle International Stadium.

Left-handed batsman Karunaratne hit eight boundaries in his sedate 82 not out with Dinesh Chandimal (18) batting with him at the break.

After home captain Angelo Mathews won the toss and opted to bat, the West Indian bowlers harassed them with short-pitched bowling but it was a fuller length delivery from Kemar Roach which earned them the breakthrough.

Kaushal Silva (17) edged to wicketkeeper Denesh Ramdin to depart after adding 56 runs for the opening stand.

As suggested by bowling coach Curtly Ambrose before the match, West Indies used their pace battery in short, sharp spells to keep them fresh in the hot and humid conditions at Galle.

Roach bowled three overs in his first spell before he was brought back into the attack and the 27-year-old right-arm fast bowler struck in the very first over of the second spell.

Lahiru Thirimanne got a reprieve after lunch when Darren Bravo dropped him at slip of Jerome Taylor but the batsman could not capitalise on it.

Thirimanne stepped out against leg-spinner Devendra Bishoo but got neither the power nor the elevation behind the shot and was caught at short midwicket to depart after making 16.