In this season’s first Celtics-76ers meeting, Boston lost at home on Christmas Day. In the second, the Celtics needed a 26-point comeback to beat a Sixers team missing two of its top three players.

The third was a much better representation of where the two Atlantic Division rivals sit in the current NBA hierarchy.

The Celtics bulldozed the free-falling 76ers on Thursday night, breezing to a 124-104 win at the Wells Fargo Center in their return from an eight-day All-Star layoff.

It was the fourth consecutive victory and eighth in nine games for the reigning NBA champions, who sit 5.5 games back of first-place Cleveland in the Eastern Conference standings. The Celtics improved to 40-16 overall and a league-best 23-6 in road games. Their average margin of victory during their four-game win streak: 19.5 points.

“I think we just picked up where we left off,” center Kristaps Porzingis told NBC Sports Boston sideline reporter Abby Chin. “We were kind of heading into the break playing pretty good basketball, and tonight we came out, threw the first punch and just really took over the game.”

The 20-35 Sixers, expected to be one of Boston’s top contenders in the East, have lost six straight and are on track to miss the playoffs.

Payton Pritchard went 8-for-15 on 3-point attempts to lead the Celtics with 28 points off the bench. Jayson Tatum excelled as a facilitator, notching a 15-point, 11-assist, 10-rebound triple-double. Jaylen Brown finished with 20 points, six assists and six boards after sitting out Boston’s last two games with knee soreness.

Derrick White had his second double-double of the season (16 points, 10 rebounds), and Porzingis topped 15 points for his 18th consecutive game (17, plus four rebounds, one steal and one block).

The Celtics were lethal and balanced from 3-point range in the opening quarter, hitting eight of their first 11 shots from beyond the arc. Those makes came from seven different players: one each by Tatum, Brown, White, Porzingis, Jrue Holiday and Al Horford and two by Pritchard, who canned threes on back-to-back possessions late in the first quarter to put Boston up eight.

Pritchard stayed hot in the second. By the 8:55 mark, the NBA Sixth Man of the Year front-runner was up to five made 3-pointers on six attempts, and the Celtics led by double digits. It was an authoritative return to form for Pritchard, who went just 3-for-18 from deep over his previous two games.

Boston’s ball movement also was terrific during this torrid start. The Celtics assisted on 15 of their first 17 made field goals, with Tatum and Brown combining for 12 first-half helpers.

One of the biggest beneficiaries of Tatum’s feeding was Luke Kornet. The backup big man converted a tough layup and two driving dunks in the second quarter, all off well-timed Tatum assists. Tatum last week called Kornet, who’s putting together the best season of his pro career, “one of the best teammates that you can have” and “a big part of (the Celtics’) success.”

At halftime, the Celtics owned a massive edge in 3-point success (15-for-25 to Philly’s 3-for-17) and a 72-56 lead. A flurry of successful Tyrese Maxey drives helped cut Boston’s edge to 10 points late in the half, but the Celtics responded with consecutive threes by Horford and Porzingis — the latter off a Tatum drop pass out of a pick-and-roll — to retake momentum.

Tatum’s triple-double was his second of the season (after his 43-point eruption against Chicago on Dec. 21) and fourth of his career. He leads the Celtics in points, assists and rebounds and is on pace for a career high in assists per game.

“(Tatum) was creating so much, and it takes a lot of energy,” Porzingis told Chin. “And tonight we were hitting shots. Sometimes he does that for us, and we’re not hitting shots. Tonight we were actually hitting shots, and lately, we’ve been shooting the ball really well. So we want to keep going this way.”

Maxey scored 33 and 34 points in the first two Celtics-Sixers matchups, but he managed just 16 points in this one and was a game-worst minus-25. The oft-injured Joel Embiid had 15 points on 3-of-9 shooting, and Boston repeatedly exploited his lack of mobility on the defensive end. Paul George scored 17 and was a minus-24.

The Celtics put the game away in the third quarter, leading by as many as 29 points and taking a 100-74 advantage into the fourth. Head coach Joe Mazzulla gave recent signee Torrey Craig some run with the regulars in the final frame (four rebounds, one assist, three blocks in eight minutes), then cleared his bench late.

A couple of garbage-time 3-pointers by Pritchard gave the Celtics 24 for the game on 54 attempts (44.4%). The league leader in 3-point makes and attempts by a wide margin, Boston has made 21 or more threes 14 times this season and is 14-0 in those games. It’s also 14-1 when shooting 41% or better from long range.

Mazzulla’s club now enters one of the most difficult stretches of its remaining schedule. Boston will play eight of its next 10 games at home, but most of those are against playoff-caliber opponents: the New York Knicks on Sunday, Cleveland Cavaliers on Feb. 28, Denver Nuggets on March 2, Los Angeles Lakers on March 8 and Oklahoma City Thunder on March 12.

Off the rim

Reserve forward Xavier Tillman missed the game with left knee inflammation. He was the only Celtics player unavailable. … Ex-Celtics guard Lonnie Walker IV agreed to terms with the Sixers on Tuesday, but he wasn’t ready to make his Philly debut against his former team. 76ers head coach Nick Nurse told reporters pregame that Walker’s contract hadn’t been finalized. … The big injury news in the NBA on Thursday was San Antonio’s announcement that second-year phenom Victor Wembanyama, the prohibitive favorite for Defensive Player of the Year, would miss the rest of the season with a blood clot in his right shoulder. Porzingis marveled at Wembanyama’s talent after the Spurs visited TD Garden last week, calling the 21-year-old “a special, special player” who is “going to be a force for a long, long time in this league.” The Celtics will play in San Antonio on March 29. … The NBA suspended Milwaukee’s Bobby Portis for 25 games for testing positive for a banned substance, which the veteran forward called “an honest mistake.” The Celtics already completed their season series with the Bucks, but Portis’ absence could impact the Eastern Conference playoff race. He’s a key reserve for Milwaukee, which entered Thursday ranked fifth in the East standings.