Pakistan Tehreek-e-Insaf (PTI) announced a series of protests from Friday
Left-handed Gayle scored most of his runs in boundaries, smashing two sixes and eight fours in his 67-ball 54 not out after the tourists elected to bat at the Galle International Stadium.
Barath, playing only his third Test, scored 50 before being caught by Mahela Jayawardene at first slip off spinner Suraj Randiv in the penultimate over of the morning session. He added 110 for the first wicket with Gayle.
Debutant Darren Bravo was unbeaten on four at the break.
Gayle took some time to settle down before playing attractive strokes on both sides of the wicket, smashing three fours in an over from left-arm seamer Thilan Thushara.
He also hit the match’s first six, lofting spinner Ajantha Mendis over long-off. He then pulled seamer Dammika Prasad over mid-wicket for another six.
Sri Lanka introduced spin after just 11 overs in a bid to break the opening-wicket stand, but Barath greeted Mendis with a fluently driven four through the covers.
Barath offered a difficult chance when on 35, but off-spinner Randiv failed to hold on to a return catch in his first over. He hit eight fours in his 86-ball knock.
All-rounder Andre Russell also made his Test debut for the West Indies.
The tourists will play three Tests, five one-day internationals and a Twenty20 match in Sri Lanka.
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