“Whether I play well or not, I know how much time I spend preparing,” McCollum said. “The only thing I saw was I had a lot of in-and-outs and I was shooting with a dead wrist. That was the only thing I noticed. I wasn’t locking my wrist out, so I just tried to lock my wrist out.”

The result was a dazzling performance against one of the NBA’s best teams early this season.

“A lot of credit to CJ. He had a heck of a night,” Bucks coach Mike Budenholzer said. “Any time we made a bit of a run or felt like the momentum might be changing, McCollum hit a big shot.”

McCollum, who entered shooting well below his career averages, went 17 for 26 from the field and added six assists.

“It was tough,” Milwaukee big man Brook Lopez said. “He made some huge plays and some tough shots that definitely were contested.”

Evan Turner had 16 points and 11 rebounds off the bench for the Blazers (8-3).

Giannis Antetokounmpo led the Bucks with 23 points and nine rebounds. Lopez shot 6 for 10 from 3-point range and finished with 22 points.

In the third quarter, McCollum put on a show. He scored 19 points and made Bucks rookie guard Donte DiVincenzo fall down on a crossover move before hitting a basket, sending the crowd into a frenzy.

“Welcome to the league,” Blazers center Jusuf Nurkic said. “It can be hard some nights. Put some ice and you’ll be fine.”

Portland led by 14 after three.

Play began at a fast pace that carried on throughout in a meeting between two of the top five offenses in the NBA. With only 16 foul shots combined, the game took less than two hours.

Portland outscored the Bucks 33-31 in the first quarter as both teams shot better than 50 percent from the floor and the 3-point line.

With Budenholzer in charge, Milwaukee is playing a much different style this season. After being a bottom-five team in 3-point attempts last season, the Bucks came in second in the NBA in 3-point tries with 41 per game. That included their 117-113 loss at Boston in which they put up 55 shots from beyond the arc. “Yeah, it’s a lot,” Budenholzer said. “The game is always evolving with teams, coaches and players trying to figure out what gives them the best chance. The skill of players now today is special, so trying to push that envelope.”