(Photo credit: Scott Wachter-Imagn Images)

Utah is quickly becoming a problem NBA playoff contenders can't solve.

The Jazz notched two straight victories against some of the league's top teams heading into Tuesday night's game against the Boston Celtics in Salt Lake City. They earned wins over Detroit and San Antonio in back-to-back days over the weekend to snap a four-game losing streak.

Against the Spurs, Utah played one of its best games of the season. The Jazz earned a 127-114 victory behind 29 points from Lauri Markkanen and 28 points from Keyonte George.

Utah has lost numerous close games this season, but the Jazz are starting to finish stronger and nab unexpected wins.

'We've seen this a bunch of times this year where we're in close games and our team is not afraid,' Utah coach Will Hardy told the Deseret News. 'They don't look scattered, they're very connected, and they're stepping up and making a lot of big plays, so I'm so proud of our group, and I want our guys and our fans to enjoy this win.'

Utah is 6-6 in December. Four of those wins have come against likely NBA playoff teams.

Improvement and development from younger players has driven success.

George is a legit candidate to be named the NBA's Most Improved Player in his third season in the league. Brice Sensabaugh and Isaiah Collier have turned into key contributors off the bench. Rookies Ace Bailey and Walter Clayton, Jr. have both shown lots of potential in their debut seasons.

Clayton, who had one of his best games to date against the Spurs, finishing with 17 points, five assists, and zero turnovers, believes the Jazz have turned a corner after compiling the league's worst record last season.

'I think guys are just tired of losing,' Clayton said in a walk-off interview with KJZZ TV on Saturday.

Boston has also made progress in December, recovering from a sluggish start and looking like a true playoff contender. The Celtics are 8-3 since the start of the month and have claimed four road victories in that stretch.

A 114-108 loss at Portland on Sunday snapped a four-game winning streak. Boston struggled from the perimeter, going 13 of 44 from deep. It caused the Celtics to let an eight-point halftime lead slip away.

Despite getting 37 points on 14-of-23 shooting from Jaylen Brown -- his ninth straight game with 30 or more points to tie the franchise record by Larry Bird (1985) -- Boston could not catch back up after falling behind the Trail Blazers in the third quarter.

For Brown, the loss shows that the Celtics still have more ground to cover in order to reach their full potential this season.

'Obviously, tonight kind of p--s me off with how we executed down the stretch, but it's an opportunity for growth,' Brown told NBC Sports Boston after the game.

The Celtics will be looking for redemption against Utah after falling at home 105-103 to the Jazz on Nov. 3. Jusuf Nurkic scored the game-winning putback basket with 0.6 seconds left.

George had his first 30-point game of the season against Boston, scoring 31 points. Brown led the Celtics with 36 points but went 0 of 9 from the arc. As a team, Boston went 11 of 51 from 3-point range against Utah.

--Field Level Media