It started on the game’s first play, when Stefon Diggs scored on a 70-yard run that saw him trot down the left sideline, reach the goal line and place the ball on the ground just inside the end zone. Later, with the rout on, running back Wes Brown spun off a would-be tackler and backpedaled the final five yards into the end zone.

There was no question Saturday whether top-ranked Good Counsel would complete the first undefeated season in school history and win its third consecutive Washington Catholic Athletic Conference title.

Rather, the only thing in doubt was the final margin and just how easy it would be for a team that will go down as one of the finest ever in the Washington area.

Brown finished with 157 yards rushing and three touchdowns while Dorian O’Daniel added 99 yards and two touchdowns as the Falcons beat Gonzaga, 42-0, in the WCAC championship game before 4,500 at Navy-Marine Corps Memorial Stadium in Annapolis.

“I didn’t expect [a rout] so much, I wanted one,” said Diggs, clutching a pair of blue-and-gold pompoms after the game. “I wanted it to be as high [a margin of victory] as possible.”

Good Counsel (12-0) led 21-0 with more than three minutes remaining in the first half and 35-0 at halftime, prompting the entire second half to be played with a running clock because of the 35-point mercy rule. At least one of its players said it felt more like a scrimmage than a championship game because of the lopsided nature.

Gonzaga (8-4) had won its previous six games since a 49-7 loss to Good Counsel on Sept. 24 and entered with plenty of confidence after consecutive overtime victories against St. John’s and DeMatha. But the Eagles never got anything going, losing three fumbles, throwing two interceptions and only once putting together a possession with more than five plays.

“We talked all week about the consequences if we got beat,” Falcons Coach Bob Milloy said. “It would have been the worst loss of my career, which is the history of football. I’ve been out here 50 years.”

The 68-year-old coach then produced a sheet of plays designed to get the ball to his star wide receiver Diggs, but it took just one to set the tone for the afternoon.

On the first snap from scrimmage, Diggs came in motion and took a handoff on a sweep to the right. With a defender preventing him from running outside and getting to the corner, Diggs cut up the field and weaved through defenders while picking up blocks before jogging the final 30 yards.

“We didn’t use too many [of the Diggs plays] but he’s that special of a guy,” Milloy said. “Sometimes a team runs the opening kickoff back and they get beat. I was like, ‘Oh, God, it was too easy.’ But it worked out pretty good.”