Rams are getting really defensive at crunch time

The Rams remain in search of their running game, but they have found a proven formula for dramatic endings.

All three of their victories, which propelled them to first place in the NFC West, came down to a final defensive play.

They clinched a win against the Seattle Seahawks by forcing a fumble. They finished the Tampa Bay Buccaneers by tackling the quarterback as time expired. And they intercepted a Hail Mary pass to secure their victory over the Arizona Cardinals.

“It would be nice,” Coach Jeff Fisher said jokingly Monday, “to have one that you can sit down and relax a little bit.”

Based on their recent history, the Rams cannot afford to let up.

Strong starts in division play are nothing new for the Rams. Last season, they swept the Seahawks, Cardinals and the San Francisco 49ers in the first half of the schedule. They also defeated the Seahawks last December to finish 4-2 against division opponents.

But they ended with a 7-9 record, their 12th losing season in a row.

So the challenge for the Rams is winning games against unfamiliar opponents outside the division.

“That’s been the case, that’s been the talk out there,” said Fisher, noting that the victory over the Buccaneers was out of the division. “So now we have to learn how to … win against uncommon opponents.”

On Sunday at the Coliseum against the Buffalo Bills, the Rams will begin a nine-game stretch against nondivision teams, including games at Detroit, in London against the New York Giants, and other road matchups against the New York Jets, New Orleans Saints and New England Patriots.

The Rams are 3-1 for the first time since 2006, when they started 4-1 but finished 8-8.

Players anticipate a different ending this season.

“People have to respect we have a lot of momentum going right now,” linebacker Mark Barron said after Sunday’s victory.

The Rams rebounded from a 28-0 season-opening loss to the 49ers to win three games in a row, equaling the longest winning streak in Fisher’s four-plus seasons as Rams coach.

“I knew that wasn’t us, knew we had to be better than that,” said defensive tackle Aaron Donald, who was ejected from the opener. “We know we made a lot of mistakes and corrected them.”

The Rams still must figure out a way to get running back Todd Gurley going.

The NFL’s reigning offensive rookie of the year has rushed for only 216 yards and is averaging 2.6 yards per carry. Gurley contributed against the Cardinals with two key receptions, but springing him for rushing yards remains a priority.

“We’re very close and he’s healthy, he’s feeling good,” Fisher said. “We just have to, obviously, put a good plan together this week.”

Protection mode

Left tackle Greg Robinson was penalized for holding on a long scramble by quarterback Case Keenum and for being too far downfield on a Keenum pass after another scramble.

But Fisher said Robinson, a third-year pro, was “doing fine” and doing a good job in pass protection.

“He’s playing hard and he’s not making the mistakes that he made as a rookie or even at times last year,” Fisher said. “He’s playing solid.”

Quick hits

Running back Benny Cunningham, who suffered a hamstring injury against the Cardinals, “felt much better” Monday and has “a chance to get on the field before the week’s up,” Fisher said. …

Fisher challenged two rulings on pass plays and lost both, costing the Rams timeouts. Fisher said he did not have the benefit of replays on the stadium video boards. “I knew I would be out of challenges with the second one, hoping that something didn’t come up later in the game,” he said. “But, in both these instances, I thought they were worthwhile based on what I saw in person.”….

Fisher played for and coached under the late Buddy Ryan, the father of Bills Coach Rex Ryan and assistant head coach for defense Rob Ryan. “They would hang around training camp in Chicago when I was playing and then I’ve followed their careers throughout,” Fisher said. “Buddy was very, very close with them. … They’re both outstanding coaches, they’re passionate. They’re coaching for their dad right now.”

gary.klein@latimes.com