Roach, who bagged five wickets in Australia’s first innings, once again rattled the visitors by dismissing opener David Warner for 17 then Shane Watson for a duck.
When lunch was taken on day four at Queen’s Park Oval, Australia were 40 for two, leading by 94 runs overall after bowling out West Indies for 257 at the start of the day.
Ed Cowan was unbeaten on 14 while former Australia captain Ricky Ponting was not out on four when rain, which has interrupted all four days of the match, stopped play before the scheduled lunch interval.
Australia polished off the West Indian innings in the first over of the day when left-arm spinner Michael Beer trapped Carlton Baugh lbw for 21.
Australia, who won last week’s first test in Barbados and only need to draw one of the last two tests to retain the Frank Worrell Trophy, made a bright start to their second innings, despite batting on a pitch that has proved hard to score freely on.
They put on 26 runs in the first ten overs after West Indies opened the bowling with Fidel Edwards and spinner Shane Shillingford.
Cowan was given a life before he had got off the mark when West Indies captain Darren Sammy dropped a regulation catch at first slip off Edwards, but the introduction of Roach into the attack quickly turned things around. In his first over, Roach angled the ball in and found the outside edge of Warner’s bat and Darren Bravo safely held a low catch at second slip. Three balls later, Roach knocked out Watson’s off stump with a good length ball that kept low.