BOSTON — Maybe it was the parquet floor, held together by brass screws and nearly 1,000 bolts.

Perhaps it was the 17 championship banners hanging overhead, so many of them earned before the Boston Celtics moved from The Garden to what is now called TD Banknorth Garden.

Or it could be all that the Celtics have done lately, like the title they won last season and the start they are off to this season.

Whatever the case, something seems to have had the Jazz spooked early in their visit to Boston on Monday night — and even power forward Paul Millsap's 10 rebounds and career-high 32 points weren't enough to overcome the fright in an eventual 100-91 loss.

Or at least Jerry Sloan thought that to be the case.

"Well," the Jazz coach said after his club fell to 15-11 at the start of a five-game Eastern road swing that continues Wednesday night at New Jersey, "it looked like we were scared to play against them to start the ballgame.

"It looked like we were afraid," Sloan added. "We wanted to play out on the perimeter and take jump shots."

Jazz players insisted they weren't in awe of the Celtics, who at a franchise-record 23-2 are off to what ties the 1995 Chicago Bulls for the third best two-loss start in NBA history — and are just three victories shy of matching the league record shared by the 1966 Philadelphia 76ers and the 1969 New York Knicks.

Sloan didn't necessarily think that was the case, either. But he had a hunch as to what was.

"Finally we got the ball inside a couple times, and started playing around the basket a little bit more, and had a little bit more success," said Sloan, whose Jazz had the Celtics tied 43-43 at halftime. "But, you know, they're awful hard to get the ball inside on, because they're a very good defensive team, and they knock you around a little bit.

"And our guys," he added, "wanted to stay outside, because I think they were afraid to get hurt. They had us intimidated a great deal."

Boston — which got a career-high 25 points from point guard Rajon Rondo, a 19-point and 10-rebound double-double from former NBA MVP Kevin Garnett, 15 points and a career-high 14 boards from center Kendrick Perkins and a career-high eight points off the bench from ex-NBA Development League/Utah Flash guard Gabe Pruitt — out-rebounded Utah 50-30.

The Celtics also led throughout the third quarter, though the Jazz were down by just four points heading into the fourth and trailed by as few as four when point Deron Williams — who battled foul trouble throughout — drove for a layup with just under three minutes to go.

But Rondo scored six points in the final 2:40 — including 4-of-6 from the free-throw line — as the Celtics won their 15th straight, marking the fourth-longest victory streak in franchise history, just three off their record 18.

That overshadowed a 12th straight double-double from Millsap, who was making his 13th consecutive start as All-Star power forward Carlos Boozer missed his 14th game in a row due a strained left quadriceps tendon and bruised kneecap.

"I thought he played his heart out to try to help us," Sloan said of Millsap, who used 13-of-20 shooting from the field and six made free throws to surpass his previous scoring best by four.

"That's the way he's been playing, for the most part. He just seems to get better and better. It's amazing what hard work will do for you."

Tough to believe, too, how a team could click as well as the Celtics have been.

"They're world champs. They make plays. That's what they do,"

Williams, who thought the Jazz were too focused on scoring early on, said afterward. "They've got a great core, and they've got guys (who) know their role."

Just what the Jazz aspire to, in other words.

"If we get both (offense and defense) clicking," said Millsap, who scored 16 of his 32 in the second quarter alone, "we're a hard team to beat.

"It's sad that we're not on that end," he added when asked about Boston's win streak moving to 15. "We could possibly be on that end at one point, but we just have to want to do it."