PASADENA — One of the bigger unknowns going into UCLA’s season opener Saturday against Bowling Green was just how the Bruins’ defense would look.

Forget about just its actual performance. The base formation, the rotations—everything was a bit of a mystery throughout the offseason.

Middle linebacker Darius Muasau and a host of transfers put the clamps on Falcons quarterback Matt McDonald and Co. and delivered a resounding performance in a 45-17 runaway victory at the Rose Bowl.

“We had a ‘so what, now what’ mentality,” said UCLA safety Mo Osling III, who tied for the team lead with five tackles.

Getting them on the field just took a bit longer than expected.

A blocked punt by PaSean Wimberly and a recovery and an 11-yard touchdown return by Charles Rosser in the game’s first 74 seconds put Bowling Green in front, 7-0, and the defense had to wait another 86 seconds to get on the field.

The Bruins’ early message was punishing and hard-hitting, setting the tone for the rest of the game with a defense that mostly showcased two down linemen with two other edge rushers upright to make up the front four. The result was nine tackles for a loss of 21 yards, including two sacks, and eight passes knocked away. All that was missing were takeaways that UCLA head coach Chip Kelly hoped to generate with all the changes to the personnel and coaching staff.