ATLANTA — He saw Jaren Hall go down, saw Brian O'Neill wave the Vikings' medical staff over with an urgency that players who are inured to football's violence only use when something's amiss. Joshua Dobbs' immediate thought was for Hall, his teammate for all of 120 hours. His next was for the checklist he'd need to hot-wire an offense he'd never run.

First, the cadence: The Vikings' starting linemen had worked with Hall in practice all week, so Dobbs gathered the group to make sure they were clear on how he'd call for the ball. "I didn't take one snap with him all week," right tackle Brian O'Neill said. From the locker to O'Neill's right, center Garrett Bradbury chortled incredulously, "You didn't take one snap with him?!"

Dobbs met with running backs Alexander Mattison and Cam Akers for a quick once-over on handoffs, practiced taking the ball from Bradbury for the first time. Vikings quarterbacks ordinarily stand next to the left tackle in the huddle; Dobbs instead stood next to O'Neill, so the right tackle strained to hear play calls as the quarterback turned his head toward the rest of the huddle. Dobbs knew some teammates only by a nickname; as for full names, "that's for this week," he said later.

The Vikings had gone 5½ seasons without starting an injury replacement at quarterback before Kirk Cousins tore his right Achilles tendon last Sunday in Green Bay. By the second quarter of their 31-28 win in Atlanta on Sunday, they'd used two: Hall, who left with a concussion after he was hit near the goal line in the first quarter, and Dobbs, who'd landed in Minnesota late Tuesday night with four days to learn the playbook after a trade-deadline deal with the Cardinals.

The comeback victory played out like the kind of race-against-time summer blockbuster that's made Tom Cruise millions, right down to coach Kevin O'Connell's role as the guy in Dobbs' ear, translating play names from his old offense to his new one in real time, guiding him through route concepts and telling him to "remember his feet." The fact the Vikings were in a no-huddle offense during their game-winning two-minute drive, O'Connell said, gave him more time to talk to Dobbs before his headset cut off with 15 seconds left on the play clock.

"It's like if you were taking [AP] Spanish all year, you showed up and Wednesday, someone told you that you have that AP French exam on Sunday," Dobbs said. "Someone's got to talk to you in Spanish and translate it to French. That's kind of what was going on out there."

The ending was appropriately climactic, as Dobbs dodged Bud Dupree's grasp and slipped away from two more tackles on a 22-yard gain that kept the Vikings alive on fourth down with 51 seconds left. Three plays later, Dobbs threw a strike to a leaping Brandon Powell, who landed on his back in the Mercedes-Benz Stadium end zone with the game-winning score on a play Dobbs had watched, but not practiced.

"I introduced myself on Thursday, and we were with him in the huddle on Sunday," O'Neill said. "He made some incredible plays; that [fourth]-down scramble was pretty insane. It was almost like we were out there playing 'Madden'; you've just got to go ball."

The Vikings arrive at the de facto halfway point of the season in control of an NFC wild-card spot that appeared out of their grasp weeks ago, as they started 0-3 while turning the ball over nine times.

Since then, they've won five of six; they have won all four of their games without Justin Jefferson, who is eligible to return from injured reserve as soon as this week. On Sunday, in their first game without Cousins, Vikings players warmed up in recently-ordered T-shirts with pictures of the quarterback. Hours before the game, David Quessenberry prepared for his first start at left tackle because of a groin injury that kept Christian Darrisaw out.

By the end of the day, the Vikings had lost Hall and wide receiver K.J. Osborn to concussions, and Akers to what the team fears is an Achilles injury. Tight end T.J. Hockenson played through injuries to his ribs and oblique muscles; Powell fought off cramps at the end of the game, convinced he'd have enough adrenaline to ignore them until the flight home. Even O'Connell's voice sounded frayed, from shouting over stadium noise to Dobbs. After the final touchdown, O'Connell threw his headset in celebration and uncoiled a Tiger Woods-style fist pump; the coach guessed he might have pulled a neck muscle in the process.

"This whole season has kind of been the story of adversity," linebacker Jordan Hicks said. "The turnover margin being as [bad] as it's been, injuries or things that have happened in-game. This team has been able to come through all that adversity."

It appeared for a while Sunday it wouldn't go that way.

The Vikings were forced to settle for a 19-yard Greg Joseph field goal, rather than sending Dobbs out for his first snap on fourth-and-goal from the Falcons' 1 after Hall was injured. Instead, Dobbs started his first series from the Vikings' 7, where Akers lost two yards on a first-down run and Calais Campbell sacked Dobbs in the end zone for a safety two plays later.

On the Vikings' next drive, with Atlanta up 8-3, Arnold Ebiketie stripped the ball from a scrambling Dobbs, and Lorenzo Carter returned the fumble to the Vikings 1. Minnesota again held a disjointed Falcons offense to a field goal, but the Vikings' offensive struggles made Atlanta's eight-point lead feel difficult to erase.

Dobbs directed a scoring drive before halftime — with the help of a 15-yard roughing penalty on Dee Alford for the hit that knocked Osborn from the game — and hit Mattison for a two-yard touchdown. But the Falcons would again take an eight-point lead in the third quarter when Jonnu Smith took a Taylor Heinicke screen 60 yards for a touchdown to make it 21-13.

The Vikings needed a spark. They got one from a defense that's been integral to their turnaround. Akayleb Evans stripped Bijan Robinson, and Josh Metellus clawed his way out of a pile with the ball at the Falcons' 40. Dobbs rolled right and escaped three tackle attempts on an 18-yard touchdown run, then squeezed in a low throw to Trishton Jackson on the run for a two-point conversion that tied the game.

Byron Murphy Jr. intercepted Heinicke on the next series, and Joseph's field goal put the Vikings up 24-21. The Falcons, though, took the lead by running 11 times in a 13-play, 79-yard TD drive that ended with six straight Tyler Allgeier runs.

It was serendipitous the Vikings needed a two-minute drill to win the game, when O'Connell could talk Dobbs through a simplified menu of plays and still have time for bite-sized direction. The Alpharetta, Ga., native grew up watching Michael Vick with the Falcons; his stirring scramble and game-winning score provided him with his own hometown moment.

"To be here on this field and have a game like that means a lot to me," he said.

Dobbs went to dinner with his parents on Saturday. The same night, he met former Vikings quarterback Fran Tarkenton, who lives in Atlanta and spoke to the team at O'Connell's request. Tarkenton met with the Vikings' quarterbacks separately; he had with him his game ball from the first win in team history, when the Vikings stunned the Bears 37-13.

O'Connell is giving the Hall of Famer a game ball from the Falcons game, too, as a token from a win that came from dozens of unlikely contributions. The most improbable might have come from the impromptu quarterback.

"I hope people understand that what Josh Dobbs was able to accomplish was very, very special." O'Connell said.