HOUSTON — Before meeting the Boston Celtics on Friday night, Ime Udoka discussed how the team has matured since his time with the organization. He said he was not surprised his former club won last season’s championship.

“It was coming regardless,” Udoka said.

Udoka says the Celtics broke through because they were able to raise their IQ and gain valuable experience. Beyond personnel changes, the team has evolved in a long list of ways since he spent one season in Boston. As much as the group has shifted since he was dismissed following what the franchise deemed an inappropriate relationship with a female employee, he surely recognized the defensive style that the Celtics used to smother the Rockets offense during a 109-86 victory.

Under Udoka, the Celtics often used Robert Williams as a roamer while Al Horford served as the primary defender of opposing centers. On Friday, Boston returned to the double-big look, but with Kristaps Porziņģis lurking in the help position while Luke Kornet took on the challenge of guarding Alperen Şengün. After the Rockets big man hurt them during the first quarter, the Celtics used the bigger lineups to shut him down the rest of the way — and, with that, dismantle the rest of the Houston offense. Boston held the Rockets to just 16 points in the third quarter, 14 points in the fourth and 26.3 percent shooting in the second half.

“Şengün’s one of the better big men in the league,” Joe Mazzulla said. “And (it helps) when you can have help behind him and just be able to have him see bodies. You first have to be able to defend at the point of attack. And so Luke was able to do that. And our guards did a great job in pick-and-roll taking away the seam catch, and when they did, KP was there to swarm him. So it was a team effort. Defensively, it was good stuff.”

Sam Hauser started the first half, but the Celtics replaced him with Kornet to begin the third quarter. That allowed them to assign Porziņģis to defend Rockets wings instead of Şengün. With Porziņģis lurking near the basket and the 7-foot-2 Kornet as his primary defender, Şengün could not approach the same success he did earlier in the game. The Celtics clamped down on Houston’s offense, which entered the game ranked a respectable 13th in overall efficiency but a lowly 26th in the halfcourt, according to Cleaning the Glass.

“Obviously, some part of it is luck, like they’re not making shots and stuff,” Porziņģis said. “But I think us forcing them to have guys that we wanted to shoot, they shot those shots, and they weren’t making them. We were making some adjustments. I don’t want to tell you all the little things we’re doing, but we’re doing some things differently and we think we just wanted to find another way how to improve. As I said, from the small sample size, it’s looking good so far.”

The Celtics committed to sending size at Şengün. They didn’t go to a smaller lineup until he checked out of the game with less than five minutes left in the third quarter. They returned to the Porziņģis-Kornet duo when Şengün subbed back in to begin the fourth. After just three minutes of the final period, Houston pulled Şengün with Boston ahead 93-72. The Celtics outscored the Rockets by 28 points over the center’s 29 minutes. He scored 14 points on 6-for-11 shooting during the first half but went scoreless on four shot attempts with two turnovers and zero assists after halftime.

On the second night of a difficult back-to-back, Boston found the effort to lock in defensively. After flying out of Minnesota late Thursday night, following a close win against the Timberwolves, the Celtics reached their hotel in Houston around 2 a.m. They played the Rockets without two key pieces in Jaylen Brown (shoulder) and Horford (rest) but still put together one of their best defensive halves of the season.

“I thought they got the better of us to start the game from a physical standpoint,” Mazzulla said. “And then I thought we did a great job responding on both ends of the floor defensively. Just the ball pressure from the guards. Playing double-big, having great rim protection, defending without fouling. I think they had 11 second-chance points in the first quarter, three in the second and then we did a great job from there on out. So I just thought we were physical at the point of attack, had great ball pressure, and then I thought our bigs gave us great rim protection. I thought Luke was fantastic on both ends of the floor. His rim protection versus Şengün and then his offensive rebounding. So that’s the standard defensively that we all know, and it was good to see the guys do it.”

Offense flowed before halftime

Before their defense dominated the second half, the Celtics built a lead with offense. While building a 65-56 halftime lead, they shot 53.2 percent from the field, including 52.2 percent on 3-point attempts, while committing just one turnover.

Jrue Holiday started them in the right direction. Early on, he established himself with an aggressive mix of drives and long 3-pointers. He overpowered defenders down low. He pulled up for an ambitious stepback 3-pointer. He intercepted a Rockets outlet pass and delivered an alley-oop to Porziņģis. Holiday scored 12 points on 5-for-6 shooting over the first 8:16. He had scored that many points in only 15 of his 28 previous appearances this season.

“I think Houston’s defense, they’re physical, they’re aggressive, so you have to respond to that,” Mazzulla said. “One, Jrue’s aggressiveness was great. In order for us to be dynamic, Jrue has to be dynamic and aggressive on the offensive end, so I loved that he came out the way that he did.”

Holiday’s early surge sparked a dominant Celtics start. They opened an 11-point lead before finishing the first quarter with a 37-31 advantage. Given the extent of their hot shot making (15-for-24 from the field, including 7 of 12 from behind the arc), the margin easily could have been even larger, but the Rockets picked up 11 second-chance points in the period. Outside of the defensive rebounding issues, the only Celtics problem early was a rough start from Porziņģis in his return from a four-game absence (ankle). The Rockets scored several baskets against him with Şengün especially effective early against the Boston center, but the Celtics solved that problem later in the game.

“It’s tough for (Porziņģis) because he’s going through a transition of coming (back) in (the lineup),” Mazzulla said. “But I thought his defense in the second half was tremendous. I thought we went to a couple things that kind of got him going a little bit on some pindowns and got him comfortable. I thought for his first game back, I thought he was great. He really helped us, especially defensively, in the second half.”

Jayson Tatum expresses fondness for Udoka

Following the first game this season against Udoka’s Rockets, Tatum suggested the coach brought the Celtics an edge they needed during his lone season with the organization. When Boston hired the coach in 2021, after Brad Stevens moved to the front office, Tatum said it was a good time for a change.

“Brad had done an amazing job for 10 years or whatever it was,” Tatum said. “Sometimes, you just need a different voice and a different style of coaching. I think Ime, he’s big on toughness and physicality and taking on the challenge and going at people. And that’s what we did that year, right? We had a tough start. But him as our head coach, he never wavered and we turned our season around. We was hungry. And got to the Finals and came up short. We loved to have him around. He’s an amazing person, amazing coach.”

Tatum said he has been blessed to play under Stevens, Udoka and Mazzulla.

“I would venture to say I’ve been very fortunate with the organization I’ve been with, with all the teammates that I’ve had, and I’ve had three of the best coaches I could have possibly had, especially at the time in my life,” Tatum said. “Brad believing in a 19-year-old kid and teaching me about the NBA and the ins and outs. At times I was frustrated with Brad and I wanted a bigger role or whatever, but I appreciate the relationship that me and Brad have and how he allowed me to grow through that process. Ime, that one year was special. First time I made first-team All-NBA, went to the finals, at that point it was the best season I had. And he instilled something in the organization that was needed at the time. Obviously, Joe, with what he’s done with this group and leading us to a championship, so I’ve been very fortunate to have three of the best coaches, those are three of the best people that I could have had and helped me on my journey.”