Ryan Clark and Jeff Saturday explain that even though it is only one game, Rams QB Jared Goff already improved a lot from last year in the team's huge 46-9 win over the Colts. (1:27)

LOS ANGELES -- The defense, without quite possibly the NFL's best defensive player, returned two interceptions for touchdowns and didn't allow a single first down. The offense, the NFL's worst each of the past two seasons, flowed in near-perfect harmony, exceeding 30 points before the midway point of the third quarter and finishing with nearly 50.

A new day, indeed, for the Los Angeles Rams.

The Rams had plenty of reason to celebrate in Sunday's opener. Robert Hanashiro/USA TODAY Sports

Playing at home, against an undermanned Indianapolis Colts team, the Rams were dominant, impressive, fun -- and through that, unrecognizable. They won 46-9 on Sunday, and in the process they scored more points than they did at any point in 2015 or 2016. A defense led by Wade Phillips, one of the most successful coordinators in NFL history, held a Scott Tolzien-led Colts offense to 225 net yards. An offense led by Sean McVay, the youngest head coach in modern NFL history, gained 373 yards, 14 shy of last year's season high.

It went down as the most points the Rams had scored in a season opener in the Super Bowl era.

McVay merely called it "a step in the right direction," but it felt more like the beginning of something bigger.

Jared Goff was calm and collected, operating behind a clean pocket and going 21-of-29 for 306 yards and a touchdown on a turnover-free day to capture his first NFL win. Todd Gurley ran hard inside and made some nice moves in space, gaining 96 yards from scrimmage and breaking several tackles for a touchdown despite some struggles in run blocking. The receivers were constantly open, with Cooper Kupp (four catches for 76 yards and a touchdown), Sammy Watkins (five catches for 58 yards) and Robert Woods (three catches for 53 yards) leading the way.

"With the additions that we've made and everything we've done in the offseason, that's how it's set up," Goff said. "There should be playmakers on the outside, and there was today."

Then there was the defense, without defensive tackle Aaron Donald, who returned from his holdout on Saturday but isn't ready to play. Even without Donald, the Rams racked up four sacks, caused three turnovers, registered a safety and brought constant pressure.

"When McVay and Coach Wade got here, they raised our accountability level, our standards, and I think guys are having fun," said Rams outside linebacker Robert Quinn, who has dealt with numerous injuries over the last two years but started to look like his old self. "It's a game, so you better have some fun. They flew around, made plays, and that's all you can really ask for. We're looking for improvements each week, but it's a good way to start."

Trumaine Johnson, a captain because of the way he handled the disappointment of not getting a long-term extension, jumped a route and registered a pick-six less than five minutes into the game. Lamarcus Joyner, transitioning to free safety and looking at an expanded role this season, did the same at the seven-minute mark of the third quarter. Nickell Robey-Coleman, filling in on the outside after Kayvon Webster was ruled out with a shoulder injury, almost did the same shortly thereafter.

The Rams became the fifth team since the 1970 merger to have two pick-sixes and a safety in a game, according to ESPN Stats & Information.

They played a bad team, but they dominated on defense without their best player, and their offense should only grow as it settles into McVay's system.

"It's a little surreal," McVay said, "but it's one game."