MOUNTAIN HOUSE — River Islands put together its most complete effort of the season on Friday, dominating in every facet in a 41-2 rout of Mountain House.

Mikey Figueroa accounted for three of the defense’s five interceptions, Isaiah Sanchez recorded a pair of sacks, Daryl Carpenter threw for 283 yards and four touchdowns and Darien East found the end zone four times, including one on a punt return.

The Riptide is now 4-0 and off to the best start in the program’s short history, but there is a sense of urgency setting in with perhaps its toughest test coming up next.

“There are always things we can fix,” East said. “We got film, 8 a.m. sharp. Everybody’s gonna be there to pick up on all the missed passes, all the missed blocks and all that. We’re never going into this with a mind set of, ‘We’re perfect,’ and we’re not leaving with a mind set that we’re perfect either.

“Everybody makes mistakes, and we’re going to have to tighten up the screws. This was not our best performance. Tonight is not our best, I promise. There’s an infinite amount of growth this team has left. We can become a very dangerous team. We can do bigger things than what we did tonight, for sure.”

The impressive receiver/safety made big plays in all phases. In fact, his final four touches of the game were an interception, a 71-yard catch-and-run touchdown, a 36-yard punt return and a 43-yard punt return to the house.

He could have returned both punts for scores, but was shoved out of bounds by Aiden Riggs-Norman on the 36-yard run-back.

East did not let that happen on the next one.

“I’m thinking, ‘He got me once; he’s not going to get me again,’” East said. “I just got done telling my teammates on the sideline that I’m either going low on my shoulder and truck him, or I was going to give him a stiff-arm. I just did that, gave him the stiff-arm and scored the touchdown.”

Defensively, East contributed a second-half interception. Roman Razo picked one off in the first half and nearly came up with a second.

River Islands held the Mustangs (1-3) to 118 yards. Mountain House used three different quarterbacks, and Figueroa intercepted a pass from each of them.

“This doesn’t just happen tonight,” Figueroa said. “It starts on Saturdays, the week before when we review film. It starts again on Monday when we push each other, and our coaches do an amazing job of preparing, breaking down film for us and making our job easier. It’s because of them we know what we’re expecting.”

Carpenter completed 21 of his 31 passes, hitting six different receivers in the process. Figueroa (three catches, 25 yards) was on the receiving end of one his four TD tosses. Christian Dell’Osso added seven receptions for 61 yards, and running back Lucas Ruiz caught three passes for 39 yards, while churning out 37 rushing yards and a touchdown on 11 carries.

River Islands did leave some points on the table early on, twice coming away empty-handed in the red zone during the second quarter. The Riptide still led 21-0 at halftime.

While the defense did not technically give up any points, the shutout was spoiled by a safety in the third quarter when Carpenter was flagged for intentional grounding while trying to escape the Mountain House pass rush from the end zone.

On its next offensive series, the Riptide fumbled a handoff that was recovered by Mustangs linebacker Mapu Sagapolu.

River Islands also committed 10 penalties.

First-year coach Nick Kendall and his staff will address these issues in practice next week as they prepare for their Mother Lode League opener with defending champion Calaveras, which also claimed the Division V-A state title last year.

“We just have to be more sound,” Kendall said. “I don’t know if anybody can really keep up with us, so if we can get a couple stops and are able to move the ball on offense, we can compete with almost anybody.”