LOS ANGELES (AP) -- Sean McVay could sense his players were coming for him with the Gatorade bucket in the final minutes.
For the first time in his wildly successful debut, the Los Angeles Rams' rookie head coach didn't use his knowledge to his advantage.
"I could have avoided it if I wanted to, but I felt like I kind of had to take it a little bit," McVay said with a grin after changing out of his soaking-wet shirt.
After everything the Rams went through last season that led to McVay's arrival, the youngest head coach in modern NFL history thought his players had earned the right to celebrate the remarkable first chapter in a new year.
Jared Goff passed for a career-high 306 yards and a touchdown in his first victory as an NFL starter, and Los Angeles routed the Indianapolis Colts 46-9 Sunday in an impressive beginning for the 31-year-old McVay.
Todd Gurley rushed for a score and added 56 yards receiving while Los Angeles roared to a 37-3 lead in the third quarter.
Trumaine Johnson and Lamarcus Joyner both returned interceptions for touchdowns as the Rams snapped a six-game skid at the Coliseum with their most impressive effort since returning home from St. Louis last year.
The Rams had their highest-scoring performance since November 2014 in their first game since McVay took over a franchise that went 4-12 last season in its 13th straight non-winning season and 12th straight non-playoff season.
The players recognized McVay's role in preparing them to blast a short-handed opponent playing without star quarterback Andrew Luck.
"Sean has had success in the past, so you know that wasn't by accident," Goff said.
Los Angeles' defense also excelled against fill-in Colts quarterback Scott Tolzien. Johnson intercepted Tolzien's first pass and returned it 39 yards for a touchdown, while Joyner returned another pick 29 yards for another score in the third quarter.
"You always feel guilty when you let your team down," Tolzien said. "(We've) got a lot to improve on, starting with me."
Tolzien passed for 128 yards in his fourth career NFL start in place of Luck, who wasn't ready to return from a right shoulder injury.
From the disastrous opening drive to an inept fourth-quarter safety, the Colts weren't competitive without their leader. Indianapolis also played without center Ryan Kelly and top cornerback Vontae Davis.
"Obviously, we were dominated in this football game in all three phases," said Indianapolis coach Chuck Pagano, who accidentally referred to the Rams as the 49ers. "Outcoached in this football game. It's my responsibility, and it falls on me."
Goff was 0-7 as a starter last season, but the No. 1 pick in the 2016 draft looked much sharper after an offseason of study under McVay. He went 21 for 29 without an interception, hitting newcomer receivers Sammy Watkins, Robert Woods and rookie Cooper Kupp for a combined 12 catches for 187 yards.
"The way we were able to execute on a lot of things today was great," Goff said.
Kupp's first NFL touchdown catch put the Rams up 24-3 in the second quarter. That's a bigger lead than the Rams held at any point over the past two seasons in St. Louis and Los Angeles, when they had the NFL's worst offense.
BAD TO WORSE
Jacoby Brissett replaced Tolzien for the fourth quarter and led Indy's only touchdown drive -- but Adam Vinatieri, who missed a field goal earlier, missed his first extra point since 2014. Brissett attempted just three passes, and Pagano didn't commit to either quarterback as the starter next week.
New Rams defensive coordinator Wade Phillips' unit also had a memorable debut, holding the Colts to 225 yards, getting four sacks and adding a fourth-quarter safety to its two interception returns. "We wanted to show that this is not a rebuilding year," defensive lineman Michael Brockers said. "We're ready to go."
Colts: Host Arizona. Luck might not be ready to return until October.
Rams: Host Washington. McVay was Jay Gruden's offensive coordinator with the Redskins for the past three seasons.