Collier (15 not out) was joined by Carroll and tasked with trying to keep Wanganui alive until stumps for the draw.
"We were all at sea," said Wanganui co-coach Rod Bannister. "The only positive thing we take out as a batting unit was yesterday. They were set, playing well, and negotiated the first five overs this morning."
Manawatu coach Mike Mason said Ben Mably made a very good catch on Steward to break up the key pair off the bowling of Isaac Harris.
The 17-year-old fast/medium pacer then went on to take his first five-wicket bag for Manawatu, while age-group Central Districts paceman Navin Patel, who had rescued his team with a well-taken 40 the day before, bagged four wickets.
Lock and Collier nicked Harris deliveries to 'keeper Mitchell Renwick, Todd Inness played all around a straight one and was bowled, and Carroll got a close LBW shout against him.
Veteran Dominic Rayner's poor run with the bat continued with a duck, and while Sam O'Leary played a couple of signature aggressive shots in the tail, an innings that had been salvaged by the 70-run partnership the day before faded away, and with it team optimism.
Bannister said 1, 2 and 6 in the batting order remain problematic.
The day before, it was a different story as Ryan Slight got Manawatu opener Luke Murray early, then picked up Renwick from a good LBW shout.
O'Leary, who had made Bannister frown with a loose ball being spanked to the boundary by dangerman Brynn Cleaver (43), immediately replied by breaking his castle for 68-3.
Collier was bowling tight spin and with Manawatu sitting at 97-5 after drinks, showed he could be an aggressive captain with four slips, gully, and just one off-side fielder.
Slight was drawing the batsmen to hit the odd chance through the air, while Ross Kinnerley was getting it straight and had a couple of LBW shouts.
From 147-8 however, Manawatu showed some pluck as Tim Richards (30) and Patel collected eight boundaries between them to take their team up to a defendable total.
After McIlraith, Lock, and Collier's departure, former CD age-group player Steward and veteran Carroll also collected eight boundaries between them and in reaching their 30s undefeated, earned warm applause at the close of play from their team-mates as the prospect of two 50s and a first-innings lead seemed all on for the morning.
But it proved a mirage as the all too frequent batting blues reared their ugly head again with seven wickets lost for only 34 more runs added.