Riverside returned one interception 25 yards for a touchdown with 1:30 left in the first half to complete a 14-point burst in a 24-second span.
The Tigers capped the scoring with a 39-yard Andre Hunt touchdown run one play after OCC freshman quarterback A.J. Josue threw his third interception.
Riverside also scored six plays after picking off a pass four plays after halftime to claim a 38-6 lead that put the game away.
OCC (1-5, 0-1), which was 1-11 in conference the last two seasons, is expected to garner more success in its new alignment.
But the Tigers, whose quarterback, freshman Dalton Livingston entered the game No. 3 in the 37-school Southern California Football Assn. in passing efficiency, showed they were no soft touch.
Livingston completed 16 of 32 attempts for 215 yards and one touchdown.
And the hosts also found production on the ground, as Hunt amassed 129 yards and three touchdowns, inclucing an 80-yard burst on the first snap after a first-quarter OCC punt.
Hunt's long run put his team up, 10-0, and he capped the Tigers' subsequent possession with a one-yard scoring run to make it 17-0.
OCC, coming off a bye week that followed its first win of the season, drove 65 yards on 15 plays to cut into the deficit, as freshman tailback Robert Penny scored on a five-yard run to make it 17-6 with 3:03 left in the first half.
But Riverside needed just four plays to answer with a touchdown of its own.
Then, Tigers' cornerback Bruce Jones broke in front of an OCC receiver near the sideline and cruised untouched into the end zone on the second play after the ensuing kickoff to make it a commanding 31-6 halftime lead.
Penny pounded away for 96 yards on 25 attempts, though he limped off the field early in the fourth quarter appearing to be favoring his right leg.
Josue, who made his second start of the season, his first since the third game, finished with 192 passing yards, including a 55-yard touchdown toss to Keali'i Doll that pulled the Pirates within 38-20 with 10:15 left in the game.