Monday night was set up to be a defining game for the 49ers, one way or the other.

A loss would have sent them spiraling to 3-6 and 0-4 in the division, without any real sign that they would be a team capable of contending for the playoffs. A win would reinvigorate a team which seemed hapless and browbeaten.

But a 49ers team which entered this week second-to-last in turnover differential (-9) flipped that script from the outset of the game. Jimmie Ward, whose absence loomed so large in last week’s embarrassing 31-17 loss to the Cardinals, was the sparkplug for the defense, and the offense resembled the well-oiled machine it was in the 2019 season.

For the first time since October 18, 2020, the 49ers won a game at home, and again, it came against the Rams, 31-10.

Ward opened the game with his first interception since 2016 on one of the more confounding throws you’ll ever see. Matthew Stafford and Odell Beckham Jr. — making his Rams debut — were clearly not on the same page, as Stafford launched a 55-yard arm punt, which Ward caught, literally catching the answer to his turnover drought-ending prayers.

What followed was perhaps the most convincing 49ers drive of the season defined by a creativity from Kyle Shanahan which had seemed lost for most of the season.

How was this creativity unlocked? Jeff Wilson Jr.

On that first drive, Shanahan used Wilson Jr. as both a decoy and a battering ram, shifting offensive personnel at a rapid-fire pace. Three times on that first drive, when Wilson Jr. came in, Deebo Samuel was motioned into the backfield as a running back, and Wilson Jr. became a lead blocker, helping to unlock all three of those carries, and taking a couple of his own.

That drive, which was an 18-play, 88-yard romp, ended with the much-missed Garoppolo-to-Kittle touchdown connection.

The obvious question after those opening series was whether they’d be the exception or the rule. That was promptly answered.

On the Rams’ fourth play of their second drive, Tyler Higbee bobbled, then dropped a tunnel screen, and Ward swooped on that ball, returning it for 27 yards and a touchdown. In one game, Ward set his season-high for interceptions, and notched just the second touchdown of his career.

While the Rams responded with a touchdown — a 10-yard completion to Tyler Higbee — that proved to be the extent of their offensive output.

Shanahan came right back with another lengthy drive, this time for 11 plays and 91 yards. In what felt like an appropriate end to that drive, Samuel took another carry lined up as a running back for an eight-yard touchdown.

That momentum never slowed. It felt like the 49ers had been pushing a boulder up a hill, and finally rolled it down the other side, directly into the Rams’ path.

And the Rams, just as the 49ers had done for much of this season, defeated themselves at every possible juncture. They entered this game with the seventh-best turnover differential in the NFL (+5), only to lose that battle 2-0. On the plays which could have wrenched them out of their situation, the Rams’ receivers were of no help.

There were at least four dropped passes; two by Higbee, one by Cooper Kupp on what seemed an easy third-down conversion, and another by Van Jefferson for a first down.

This is now the fifth-straight game in which Kyle Shanahan has beaten Sean McVay. It certainly seems like there’s a complex going on between Shanahan and his disciple.

Above anything else, the questions we’re left with are: where has this been for most of this season, and can the 49ers replicate this performance?

All the things which have plagued them, and damningly so, this season — losing the turnover battle, penalties and a failure to convert on third down — were erased.

San Francisco won that battle, committed a negligible amount of penalties (nine for 53 yards), especially when the game was in the balance, and converted on third down, going 8-for-13 in that respect.

It was done with Jimmy Garoppolo at his most efficient, almost solely targeting receivers over the middle of the field. He hit the YAC Bros — George Kittle, Deebo Samuel and Brandon Aiyuk — to the tune of 13 completions for 173 yards. They were hit on time and in-stride for the most part, and involved from the outset.

Garoppolo finished 15-of-19 with 182 yards and two touchdowns, and was asked the most of on third downs, where he was excellent.

Shanahan leaned heavily on the run game and asked Garoppolo to make those on-schedule throws, as Elijah Mitchell (27 carries, 91 yards) led a consistent rushing attack which combined for 44 carries for 156 yards. Samuel had the only rushing touchdown of the day.

This team still has myriad questions to answer, and we still have nothing definitive to say about which side of the two-faced coin will land on a week-to-week basis. But what was evident is that they walloped a 7-2 Rams team doing most of the things which have made them successful in the past.

One thing that still looms as a potential issue, though, is their defensive line, which finished with two sacks, and left Stafford largely with a clean pocket. That might be nit-picky on a wildly impressive night in Santa Clara, especially with their coverage taking a substantial step up, but without a consistent pass rush, it makes it tougher to know how likely this performance is to be replicated.

Still, this is a step in the right direction for a 49ers team that says it still expects to compete this season. Now it’s time for another one in the same direction.