The Los Angeles Rams entered the first game of their new NFL campaign looking to live up to their pre-season hype.
Instead, they've been dealt a harsh reality check and will need to quickly scramble to pick up the pieces.
"We knew we were going to face some adversity in the season and we've come to find out that it's game one," coach Sean McVay said.
"We've got to find out if we're as resilient as we say and as much as we've shown throughout the pre-season."
A 27-7 defeat to bitter rivals San Francisco at the MCG was a shock result, considering the Rams were lauded as Super Bowl favourites after a stellar off-season recruiting period where they attracted the dazzling names of Myles Garrett, Trent McDuffie and Aaron Donald.
The additions joined an already star-studded side which reached the NFC Championship game last season.
All eyes were on Garrett on Friday, after he was traded by the Cleveland Browns for an stunning $US208 million ($A290 million) and was fresh from a sparkling campaign where he was awarded the AP defensive player of the year.
But he posted zero tackles and zero sacks in front of 100,021 fans.
"This was the worst version of myself that I've put out there," Garrett said after he dealt with a knee issue during the game.
"I've got to be better. I've got to find a way to recover and get back to the player I know I can be and that I've shown that I can be before."
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Although the Rams will get on their 15-hour flight home in a state of shock, the 49ers will be much more positive.
San Francisco reminded their divisional rivals of just how dangerous they are with a healthy roster, after their hopes of winning a ring last season were cruelled by a plethora of injuries.
It wasn't just their returning players who shone though, as Niners recruits Deebo Samuel Sr. (one touchdown, 48 yards) and Mike Evans (one touchdown, 49 yards) were prolific.
"It was just so good having him (Samuel) back," teammate Trent Williams said.
"Having his impact back in the locker room, and his leadership for those young guys, I mean, it's clutch.
"He (Evans) made the plays like he normally does. He's a jump ball extraordinaire and ... it (the performance) was definitely what we expect to see out of Mike."
San Francisco will hope wide receiver De'Zhaun Stribling (ankle) and tight end Jake Tonges (MCL) are fit for the Miami Dolphins' visit next Monday (AEST), while the Rams host the New York Giants on Tuesday.
