Grant Mason came off the bench to score a game-high 21 points to lead St. Ambrose to a season-opening 66-48 win over Grace Christian Friday on the first day of the Calumet Wave Classic in Whiting, Ind.

On a night when both teams struggled offensively, Mason knocked down 8-of-15 attempts from the floor in scoring a new career high.

SAU built a double-digit lead midway through the first half but led just 32-29 at the break thanks to a Solomon Garrison 3-pointer in the final seconds of the half.

The second half saw the two teams combine for just two threes, and they both came from St. Ambrose in the opening minutes. Mason and Collin Wainscott hit from beyond the arc to spark a 10-2 run. Guillermo Narbona capped the spurt with back-to-back layups to extend the Bees' lead to 42-31 just over three minutes into the second half.

After a Grace Christian free throw, Mason and Narbona went back to work. The duo split the game's next eight points as the margin ballooned to 50-32 with 14 minutes remaining. SAU was not threatened the rest of the way.

The Bees outscored the Tigers 34-19 in the second half. St. Ambrose did it with its defense. Grace Christian (0-1) was just 8-of-30 from the floor over the final 20 minutes. That included an 0-for-11 mark from 3-point range. SAU also forced 11 second-half turnovers.

For the game, Grace Christian shot just 30 percent overall (18-of-60) and less than 14 percent on threes (3-of-22).

St. Ambrose, which shot just 42.4 percent from the field (28-of-66) and 17.4 percent from deep (4-of-23), saw Narbona finish with a double-double of 14 points and 15 rebounds. He was 7-of-11 from the field.

Garrison finished with seven points while Will Spriggs and Alec Platipodis each scored six. Ignacio Dacunda scored five points to go along with 14 rebounds and four assists. Wainscott also threw in five points. Zane Witt added two points.

SAU will wrap up the two-day classic against Moody Bible Saturday.