The old record was set by Golden State's Stephen Curry in 2009-10.
"That's an honor to be able to do that, in my first season," Lillard said. "But I wish I would have done it in a win. So it's bittersweet."
Noting the record he broke was set only three years ago, Lillard added, "I think now, in the league, guys shoot a lot more threes than they did in the past. So it takes away a little of the significance. But it takes a good shooter to be able to do it and I'm happy I was able to."
According to Portland coach Terry Stotts, Lillard's accomplishment puts another exclamation point on a sensational season.
"I'm happy for him," Stotts said. "It's something to be proud of anytime you set an NBA record. There have been a lot of rookies in this league and that 3-point line has been in since '79. So that's impressive."
One year ago, Lillard had just finished his collegiate career at Weber State. He was awaiting the NBA draft, where he was the eventual No. 6 overall pick.
The dizzying speed of his journey to a likely Rookie of the Year award makes Lillard shake his head.
"It kind of blows my mind how fast things happen," he said. "It seems like I was just [at Weber State] and now I've played almost a whole NBA season."
Before the game, Lillard greeted a handful of Wildcat fans, including his former coach, Randy Rahe.
"It was good to see a lot of familiar faces," he said. "But, like I said before, it's bittersweet to come here and lose the game."
Lillard did his part.
He scored 17 points, handed out five assists and grabbed five rebounds.
Still, Portland lost its fifth straight game by allowing Utah to shoot 54 percent.
Asked about the Blazers' effort, Lillard said, "I thought it was up-and-down. Defensively, we weren't nearly as consistent as we needed to be." • Ex-Weber State star Damian Lillard breaks the NBA record for three-pointers by a rookie.
• Lillard has 17 points, five rebounds and five assists, but the Jazz defeat Portland, 112-102.
• The loss was the Trail Blazers' fifth straight and dropped them to 1-3 against Utah this season.