The former Malmo striker only flew into the country on Sunday after finally being handed a visa and, having had just one training session with his team-mates, he was thrown into the action with 55 minutes on the clock.
The Cherries' top scorer Lewis Grabban had already missed a gilt-edged chance to break the deadlock but the arrival of Rantie sparked the home crowd and their team into life.
Within seconds of his introduction he twisted and turned and bent a shot inches wide, and his pace kept the Tykes defence on their toes as the Cherries upped the ante.
And, even after Marc Pugh drilled home the only goal, Rantie had a chance to make things comfortable but, despite his failure to find that dream debut goal, his new manager was full of praise.
"I thought he did well, these are big changes for him," Howe said. "I thought he did so well, and the first thing he did was nearly score.
"He made the difference and I thought that front three worked really well.
"It was an easy decision (not to start him) purely because he has had one training session with us and a long flight.
"There is certainly not any pressure from me but obviously I know there is media and fan expectation but I know he will do his best, give everything he can for the club and the rest is in the lap of the Gods.
"With the ability he has got I am sure he will be a big success."
And while Rantie's arrival boosts Howe's options he could make the long trip to Middlesbrough without defender Charlie Daniels.
"We think it is a re-occurrence of Charlie's heel injury, so we will have to wait on that," he said.
"We will see how it settles down. But this victory sets us up nicely for a tough few games.
"They are a tough side and they will beat some big teams this year - for me this was one of our most difficult games so far."
Barnsley's first-half display in particular belied their status as one of the league's strugglers and they were incredibly unlucky not to head into the break with a one-goal lead as Chris O'Grady and then Steve Dawson both rattled the same post in the same move.
And they continued to create chances throughout the 90 minutes and only a fine block denied substitute Jason Scotland a late leveller.
And manager David Flitcroft was pleased with the hard-working display from his side, despite the final outcome.
"I told the players to give it everything and they have done," he said. "They put everything I asked of them into a football match and it wasn't good enough to get anything out of the game.
"Certainly in the first half I was delighted with the way we played and in the second half they got on top of us and we couldn't stop them at times.
"We still had chances; the two that hit the post in the first half and on another night they go in and we comfortably win the game.
"I can't ask anything more from that group of players - they work hard for each other and give it everything.
"We came here to win the game and I've thrown everyone on and gone really positive. I've told the lads after the game to keep working hard."