CARSON, CALIF. – On the most important drive of the Ravens’ season, their defense was on the field, and for that they could be grateful. There has not been a defense as consistent or as constricting as the Ravens’ all season. When the offense has struggled or special teams have sagged, the Ravens had the ultimate fail-safe.

The unit could be dinged only for one thing: It could not, would not force turnovers. The Ravens entered Saturday night’s must-win game against the Los Angeles Chargers with the second-fewest takeaways in the NFL.

But this wild, unforgettable, so-strange-it’s-true Ravens season has been nothing if not one of continual reinvention. And when the moment called for it, there was overlooked inside linebacker Patrick Onwuasor, punching the ball loose from Antonio Gates a split-second before the tight end was down. There was Tavon Young, the slot cornerback with a nose for loose balls, picking up the fumble and sprinting down the sideline. There went the Ravens, about to put away maybe the AFC’s hottest team with a 62-yard defensive touchdown and 22-10 victory, likely moving just one victory away from their first playoff appearance since 2014.

“Our defense, that’s an ass-whooping,” rookie tight end Mark Andrews said. “That’s plain and simple. And they do that to everybody, so they’re incredible to watch.”

With the win at StubHub Center, the Ravens (9-6) authored another defensive masterclass — 198 yards allowed, three turnovers forced — and made their playoff path straightforward. If the Pittsburgh Steelers lose today to the New Orleans Saints, the Ravens need only to win their regular-season finale against the visiting Cleveland Browns to claim their first AFC North title since 2012. That would secure at least the No. 4 seed and a home game in the wild-card round. A rematch with the Chargers (11-4) in Baltimore could beckon.

The Ravens have cover even if the Steelers win out. While the Tennessee Titans (9-6) and Indianapolis Colts (8-6) will likely meet next week in Nashville with matching records, a 10-6 Ravens team would win a wild-card tiebreaker over either. The Titans lost their all-important head-to-head matchup to the Ravens in Week 6, and the Colts’ AFC record with a win in Week 17 (7-5) would be worse than the Ravens’ (8-4).

Two straight losses by the Houston Texans (10-4, 8-3 AFC) could muddy the playoff picture, but the Ravens’ mission is clear: Win and they’re probably in.

“We feel like we need to win,” said John Harbaugh, whom the Ravens announced would return as coach in 2019 on Friday night. “That’s it, we just need to win. That’s been the thing, just win. Just win baby. I think a famous, well-revered football man said that. That’s where we’re at.”

Saturday’s victory was not easy. It required a couple of career highs through the air from Lamar Jackson. He finished 12-for-22 for 204 yards, his first time over the 200-yard threshold, and the highlight went to a favorite target.

A month ago, Jackson found Andrews for a career-high 74-yard completion — but the catch-and-run ended short of the end zone. On Saturday, with the Ravens trailing for the first time all night, 10-6, Jackson delivered a perfectly placed pass to Andrews over the middle. Andrews, only 23, delivered a grown-man stiff-arm to safety Jahleel Addae and coasted to the end zone, safety Adrian Phillips in his wake.

“Mark got open, made a great catch, the stiff arm — I know y’all seen that,” said Jackson, who was limited to 39 yards rushing but improved to 5-1 as a starter. “Y’all have that on ESPN. And he was just off to the races. He didn’t get caught from behind like Oakland, man. He did a great job.”

Ravens kicker Justin Tucker earned a measure of redemption with a 56-yard field goal on the Ravens’ next possession, but from there, there was little room to breathe. They went three-and-out on their next three possessions, saved over and over by a defense that forced the Chargers into four straight punts and allowed two second-half drives longer than 17 yards.

The Ravens could not have scripted a better first two plays from scrimmage Saturday. On the Chargers’ first play, quarterback Philip Rivers (181 passing yards, no touchdowns, two interceptions) underthrew a deep pass down the right sideline to wide receiver Mike Williams. Cornerback Brandon Carr, who had stumbled as Williams looped around him, high-pointed the ball and secured an interception against his shoulder pads with his left hand as he fell to the ground.

The next play rated lower on the difficulty scale. Running back Gus Edwards tore through the heart of the Chargers defense almost untouched for a 43-yard gain. The game wasn’t even a minute old, and already the Ravens had moved within 9 yards of the end zone.

But the offense stopped right around there. That would become a theme throughout the first half. All five of the Ravens’ first-half drives ended in Chargers territory. Only one of the Chargers’ five first-half drives ended in Ravens territory. But at halftime, the Ravens’ lead was only 6-3.

The culprits were surprising. Tucker, just days after his Pro Bowl snub, missed a 53-yard field goal on the Ravens’ second possession. The next time down, the Ravens passed on a gimme look for Tucker to go for it from the Chargers’ 2-yard line. Jackson threw his pass out of the end zone.

After running back Kenneth Dixon fumbled on the Ravens’ first play from scrimmage in the second half, running back Melvin Gordon needed just three plays to find the end zone, capitalizing where the Ravens at first could not. The Chargers hadn’t even cracked 100 rushing yards, but already the game had begun to swing wildly.

The game could’ve pivoted on that turnover. The Ravens wouldn’t let it; they forced the biggest one themselves.

“We just let the game come to us,” Onwuasor said. “We work on it every day in practice, but we just flow with the game. If it comes, it comes. If it don’t, it don’t. But what we wanted to do is play physical defense, and that’s what we are.”

jshaffer@baltsun.com

twitter.com/jonas_shaffer