Kanter and Favors combined for 21 in the fourth quarter for Utah, which lost 120-114 to Portland on Monday. Kanter also finished with 12 rebounds.
The preseason game was tight throughout until Kanter and Favors took over midway through the fourth.
"We both played good," Favors said. "We came out and played hard and gave a lot of energy."
Utah's reserves outscored the team's starters. Jazz point guard Mo Williams rested for precautionary reasons.
The Blazers, who open the regular season on Wednesday against the Los Angeles Lakers, committed 25 turnovers and went 5 for 21 from 3-point range.
"There were 25 turnovers where we just gave them the ball," coach Terry Stotts said. "When over a fourth of your possessions are giving the ball to the other team, that's hard to win like that."
Portland rookie Damian Lillard, who played his college ball just up the road for Weber State, was 4 for 14 from the field and finished with 12 points. The point guard also committed five turnovers after scoring 21 points on 6-of-8 shooting in Monday's victory.
"It's always tough against a team two times in a row," said Lillard, who was cheered by more than 100 Weber State fans, boosters and coaches. "They came out, they played physical, they were active and they made plays that we didn't. As for me, I missed some good looks and probably could have taken better care of the ball. But they played a great game."
The Jazz used an 8-0 run to open an 85-78 lead in the fourth quarter. Favors and Kanter finished off the surge with consecutive jumpers.
Portland led 47-45 at halftime despite going 2 for 11 from long range. Matthews went 5 for 6 from the field in the second quarter and had 14 points at the break.
Utah showed off its front-court depth during one impressive display in the first half, with Kanter blocking Meyers Leonard and Favors jamming at the other end on a pass from Jamaal Tinsley to tie it at 41 with 3:21 left. Favors also converted a three-point play after a steal and nice pass by swingman DeMarre Carroll.
Al Jefferson led Utah's starters with 15 points and nine rebounds.
"I really liked the way the starting group came out in the third quarter with a sense of urgency and got us going," Jazz coach Tyrone Corbin said. "Then the group that finished did a great job of understanding what it takes to finish."
Randy Foye started in place of Williams, who was held out by coaches after dealing with a strained groin in preseason. . Stotts said he would make final roster decisions Saturday. . Corbin received a technical foul late in the first quarter.
The Toronto Raptors suffered a major rout in Game 5 of the East finals 116-78, falling behind the Cleveland Cavaliers 3-2.
LeBron James scored 23 points then grabbed a seat, Kevin Love scored 25 and the Cleveland Cavaliers unleashed tenacious defense on Toronto to regain control of the Eastern Conference finals.
Toronto fans have nothing to cheer for in Game 5.