It wasn't meant to be for the Utah (11-18, 4-14), which next plays at the Pac-12 tournament Thursday in Seattle.
Utah, the No. 11 seed, plays sixth-seeded Washington at 9:30 p.m. on Thursday in the first round.
Pac-12 women's bracket
The Utes admit they never imagined they'd be heading into the tournament after such a year of struggles.
"We felt pretty good after last season," Plouffe said. "Then people went down and stuff came up and stuff happened and it was like we were always waiting for it to come together instead of making it happen. It never did and now it's the end."
Sunday's game was a microcosm of the season in coach Anthony Levretts mind as Utah blew a seven-point, second-half lead.
UCLA's Nirra Fields proved to be the party crasher as she made one big play after another to lead the Bruins (13-17, 7-11) with 22 points, five assists and four rebounds.
After UCLA rallied and went ahead, a layup by Plouffe tied the game at 43-43 with eight minutes to go, but instead of sparking a Utah comeback the bucket seemed to liven the Bruins, who answered with a 7-0 run that included a Fields' 3-pointer.
Then, with two minutes remaining, Fields stole the ball and raced to an uncontested layup for a 56-50 lead.
After a Utah miss at the other end, Fields got the rebound fed the ball to Atonye Nyingifa for a bucket that all but put the Utes away.
Plouffe finally stopped the onslaught when she made a basket that cut UCLA's lead to 58-52 with 1:23 to go, but it was too late.
Plouffe finished with 20 points and four rebounds, and Emily Potter added 14 points and eight rebounds.
Nyingifa tallied 16 points and nine rebounds, Corinne Costa had 15 points and eight rebounds for UCLA.
Fields scored 17 points in the second half and finished 13 of 17 at the free-throw line.
"She is just a very talented player," Levretts said. "She is as physical a player as you come across and she was a big challenge. For us it is just something different every single night that gets us."
Pac-12 women's basketball
UCLA 62, Utah 52
O In short • Utah can't contain UCLA guard Nirra Fields, who scores 22 points, as the Bruins take the win, dropping the Utes to 7-8 at home in 2014.
Key moment • Nirra Fields gets a steal and made a layup with two minutes to go that puts the Bruins ahead 56-50.
For the women's tournament bracket, visit http://pac12.me/1cw9TcJ