Marlon Samuels helped the West Indies rebuild on Friday afternoon but they remain in trouble on day two of the second Test against New Zealand.
Just 51 runs were added in the morning as the hosts lost three wickets, with Chris Gayle batting an hour and three quarters for just eight.
Two more quick wickets after the restart had them deep in trouble at 83 for five and although Samuels reached tea unbeaten on 79, his team remained 97 runs adrift on 163 for seven.
Kieron Powell failed to add to his overnight 10 before edging an excellent Trent Boult outswinger to Dean Brown low at third slip. And the left-armer had his second victim of the morning when Assad Fudadin played across one that kept low and was given out lbw after a referral without scoring.
As Samuels advanced into the twenties at almost a run a ball, Gayle's oddly strokeless vigil continued for much of the morning. He was dropped by Ross Taylor off Southee but there was no repeat of the first Test, when he punished a dropped chance by making 150.
He was beaten by a ball from Wagner, who then celebrated two deliveries later after the ball looped off the shoulder of Gayle's bat to BJ Watling at point.
Samuels' rapid start included four boundaries and he hit another off Southee to move to 28 before he too went into his shell, reaching lunch 30 not out from 63 deliveries.
Shivnarine Chanderpaul was on eight at the other end and added only one more upon the resumption before edging Southee to Taylor at slip, and Boult had Narsingh Deonarine caught behind for a five-ball duck.
But Samuels kept his focus and crashed Boult to the long-off boundary to reach a 93-ball half-century and kick-start a stand of 30 with Denesh Ramdin. The wicketkeeper made 15 before Wagner's extra bounce again did the trick as he edged to Kane Williamson at gully.
Darren Sammy demonstrated his unorthodox take on the captain's innings as he hammered a typically carefree 32 from 29 balls with six boundaries in a stand of 49 with Samuels, who will now need the support of the tail if he is to reach his century or help his team match the tourists' first-innings total of 260.