The American Airlines Center was filled with Cooper Flagg jerseys ahead of his highly anticipated debut, but San Antonio Spurs center Victor Wembanyama stole the show with one of the best performances of his career.

The 7-foot-4 center finished with 40 points, 15 rebounds and three blocks, leading the Spurs to a 125-92 win over the Mavericks on Wednesday night.

While Wembanyama looked every bit like an MVP candidate, Flagg struggled to find his rhythm. The Mavericks’ No. 1 overall pick scored 10 points but made only 30.8% of his shots. Starting at point guard appeared to limit his scoring opportunities.

With reigning Rookie of the Year Stephon Castle, who started at point guard with Spurs guard De’Aaron Fox out, guarding him for much of the game, Flagg had difficulty creating space. The Mavericks tried to free him with screens in the first half, but little worked.

Flagg came alive in the third quarter, scoring six straight points for the Mavericks by using his 6-foot-9 frame to attack the paint. His best moment came on an up-and-under layup where he hung in the air before finishing through contact.

Flagg didn’t get much help from his teammates. The Mavericks shot under 40% from the field, while the Spurs topped 55%.

Anthony Davis added 22 points and 13 rebounds but was limited by four fouls. PJ Washington was a bright spot, contributing 17 points and five rebounds in the loss.