Tea Sri Lanka 146 for 2 (Fernando 29*, Chandimal 0*) and 258 (Thirimanne 55, Nissanka 51, Roach 3-58) need another 231 runs to beat West Indies 354 and 280 for 4 dec (Brathwaite 85, Holder 71*, Mayers 55, Lakmal 2-62)
Sri Lanka lost their openers after lunch, but a draw continued to be the most likely result thanks to the platform Dimuth Karunaratne and Lahiru Thirimanne had set with their 101-run first-wicket partnership.
Karunaratne went on to 75 - his first significant score of the tour, before being dismissed shortly before tea by Kyle Mayers, who seamed a ball into his back pad and claimed an lbw decision. For much of the session, Karunaratne had Oshada Fernando for company - Fernando himself having been given lbw against Mayers only for the decision to be overturned on review.
By tea, Fernando was on 29 off 58, and had Dinesh Chandimal for company. Sri Lanka appear to have given up hopes of chasing 377 down (it had been a remote possibility anyway), but seemed on track to finish the series 0-0.
West Indies, meanwhile, were hampered by the absence of Shannon Gabriel, who left the field two balls into his sixth over with what seemed to be a hamstring complaint, and appears unlikely to bowl again in the game. Thanks partly to his absence, captain Kraigg Brathwaite has tried eight bowlers in the innings. Only Alzarri Joseph, who took Thirimanne's wicket, and Mayers have been successful.
Thirimanne had fallen the fifth over after lunch. He'd been dropped on 17 early in the morning session, but had been cautious since then, venturing only two boundaries all the way through till lunch. Perhaps distracted by a bail behind him that kept falling off due to the wind, Thirimanne played a loose drive to a full delivery outside off stump from Joseph, and nicked off to second slip for 39 off 114 deliveries - Rahkeem Cornwall taking a sharp, low catch.
Karunaratne, who had completed his half-century just before lunch, slowed down significantly after Thirimanne's wicket, signalling that Sri Lanka were going to hunker down and secure the draw. Right through the innings, he was adept at shuffling to off and closing the face of the bat, to pick gaps through the legside, where he scored 55 of his runs. All but one of his nine boundaries came on that side of the field.
West Indies's bowlers were disciplined right through the day, but neither in the morning session, nor after lunch did the pitch offer them much to work with. Cornwall occasionally threatened with the substantial drift he was getting, but apart from the occasional ball that misbehaved off the rough, there was still no sharp turn on this surface. The seamers, meanwhile, could get little bounce or pace out of the pitch - the odd ball that did take the edge dropping well short of the catchers.
The only real mistake the hosts made in the day was wicketkeeper Joshua de Silva shelling that fairly straightforward chance off Thirimanne, who had gloved Alzarri Joseph down the legside. It would take something heroic for them to force a result from here.
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf