The victory gave Lara's side a 3-1 lead in the five-match series, and was West Indies' first major triumph in a ODI series under any format, since they clinched the ICC Champions Trophy in England two years ago.
"There is a new feeling in the team, and we are being positive, we want to win, we are going to grab every opportunity that we have to win," said Lara.
"This is what is going on with this side. It does not matter what situation we find ourselves in. There seems to be a lot of good thinking, calm thinking, and the guys are moving forward, and are looking to put themselves in a position to be successful."
One of the things that pleased Lara, who made 69 from 95 balls on Friday, was the all-round effort of the team.
"I am very proud of the guys because they played really well," he said.
"We are sharing the responsibilities. We have had Ramnaresh Sarwan, Chris Gayle, Shivnarine Chanderpaul, and Runako Morton, it is good to see everyone making a contribution, and that is what is very, very good about this team."
Indian captain Rahul Dravid blamed the unfamiliar conditions in the Caribbean for his side's inability to keep up with the West Indies.
"Especially with the batting, the slower pitches were not conducive to strokeplay, and they bowled in good areas, so we have not been able to get the kind of totals that were expected of us," he said.
"We have struggled to get use to the conditions and their spinners, in particular, have come on at crucial stages in the games and tied things down and taken wickets. This is something we can work on and something at which we can better.
"It has been a good experience for us, and we have learned a lot about these pitches. It is something we will take away with us, and hopefully, we can come back better next time."
Dwayne Bravo, whose three wickets and undefeated 61 gave him the man-of-the-match award, was delighted at playing an important role in another West Indies victory as his side successfully chased a target of 218.
"We all know that Dwayne Bravo has a lot of ability in terms of bowling, but last night at the team meeting, the skipper said that Ramnaresh Sarwan, Chris Gayle, Shivnarine Chanderpaul had all played well in previous games, and it was up to someone else to come out special in this game," Bravo said.
"This was the real game. This was the game that really counts and all of us were looking forward to it, and it's nice for me to know that I am Man-of-the-Match on my club ground and in front of my fans."
The series concludes on Sunday at the same venue.
India won the series opener at Kingston by five wickets with one ball to spare, but West Indies rebounded to prevail by one run with two balls to spare in the second ODI at the same venue, and by four wickets with one ball to spare in the third ODI at Basseterre.
The ODI series will be followed by a four-Test series.