Lars Eller scored the tiebreaking goal with 7:37 to play, and the Capitals raised the Stanley Cup for the first time in franchise history after a 4-3 victory over the Vegas Golden Knights in Game 5 on Thursday night.

Devante Smith-Pelly tied it with a full-stretch goal midway through the final period of the Capitals’ fourth consecutive victory over the Golden Knights, whose incredible expansion season finally ended in the desert.

So did the Capitals’ agonizing wait for their first championship since the franchise’s debut in 1974. After so many years of postseason flops and crushing disappointment, these Capitals won their fourth consecutive closeout game with a tenacious third-period comeback.

Captain Alex Ovechkin, who scored an early power-play goal, and his teammates are Washington’s first championship hockey team — and the city’s first champion in a major pro sport since the Redskins won the Super Bowl in early 1992.

Ovechkin won the Conn Smythe Trophy as the playoff MVP after scoring his franchise-record 15th goal of the postseason. When he received the Cup from NHL Commissioner Gary Bettman, he shouted “Yeah! Yeah! Yeah!” through his gap-toothed grin before skating away and hoisting the prize over his head for a victory lap in front of thousands of red-clad fans.

“We did it,” Ovechkin said. “That’s all that matters. Look at the smiles on my teammates. This is something you’ll never forget. This moment, I’ll remember for the rest of my life. I’m so happy. It’s unbelievable.”

After Vegas won the opener, the Capitals capped their four-game surge by rallying from a third-period deficit in this cathartic Game 5, banishing so many years of playoff failure with big goals and rugged play across their lineup.

Braden Holtby made 28 saves in Game 5, outplaying three-time Stanley Cup champion Marc-Andre Fleury in the other net one final time.

The Caps couldn’t win a Cup without a little late weirdness, however: The game clock stopped working on the T-Mobile Arena scoreboards during the final minutes, and the Capitals angrily protested while they played on. Vegas never got close to a tying goal. Reilly Smith scored a go-ahead goal late in the second period for the Golden Knights, who won seven of their first eight home playoff games before dropping the last two.

The defeat ends the incredible inaugural season of the Golden Knights, who became the NHL’s 31st franchise last fall and immediately launched into arguably the greatest debut in modern pro sports history.

Nate Schmidt and David Perron also scored for Vegas in the second period, but Fleury’s 29 saves included a stopped puck that dropped underneath him where Eller could sweep it home for the Cup-winning goal.

Washington’s win was its 10th on the road in this postseason, tying the NHL playoff record and illustrating the superior toughness of this team. While past editions of the Caps created their team’s reputation for postseason flops in part by losing five playoff series in which they had won three of the first four games, Ovechkin’s latest group promptly closed out all four of its series this year on the very first try.

The remarkable Golden Knights hadn’t lost four consecutive games in their entire inaugural season before the Caps rolled them.

The Capitals had thousands of fans in the Vegas crowd and a building full of supporters watching back home along with countless thousands outside in the crowded D.C. streets. They got a barn-burner of a finale befitting this thrilling series, with wild shifts of momentum before that bizarre clock incident that didn’t appear to affect the outcome.

Ovechkin, who turns 33 later this year, has been among the most exciting and productive players in his sport since joining the Caps in 2005. Yet for all of his goal-scoring prowess and athletic swagger, the Great Eight had never won an Olympic gold medal or a Stanley Cup title.

But after becoming the fifth player in the last quarter-century to score at least 15 goals in a postseason, Ovechkin is a champion at last. He also became the first Russian captain to raise the Cup in NHL history.

The title is also validation for Holtby, who has spent his entire NHL career in Washington. After several seasons of being measured unfavorably against Fleury and other goaltending greats despite his 2016 Vezina Trophy, the Saskatchewan native also has his long-sought ring.

Shortly after Jakub Vrana scored the opening goal of Game 5 on a breakaway early in the second, Schmidt tied it when his fling toward the net deflected off a stick and again off Caps defenseman Matt Niskanen’s skate.

Vegas’ Brayden McNabb took a penalty just 11 seconds later, and Ovechkin set up in his customary spot in the left faceoff circle to put Nicklas Backstrom’s cross-ice pass into a sliver of open net.

Perron battled with Washington’s Christian Djoos in the crease moments later and eventually ended up inside Holtby’s net while Tomas Tatar’s shot glanced off him and in. The Caps challenged for goalie interference, but were denied.

And with Ovechkin in the penalty box for tripping in the final minute of the wild second period, Smith scored into a mostly open net after controlling a pass from Alex Tuch. The teams then engaged in a brawl behind the net, reflecting the unbearable tension with the Cup on the line.

Washington pressed early in the third, but didn’t connect until Brooks Orpik created a chance by stopping the puck at the blue line and flinging it to the net against the run of play. Smith-Pelly barely controlled the puck and stretched out to fling it toward the net while falling face-forward, and it slipped inside Fleury’s post for the veteran forward’s seventh goal of the postseason — matching his total from the entire regular season.

Moments later, the Knights struggled to keep up with the Caps’ puck movement and Brett Connolly open for a shot. Fleury stopped it, but the puck fell to the ice underneath him — and Eller fought off Luca Sbisa and slapped the stationary puck into the net for his seventh goal of the postseason.

NOTES: The Knights made two lineup changes from Game 4, inserting Perron and William Carrier while scratching Ryan Reaves and Ryan Carpenter. Carrier hadn’t played since the second round against San Jose, while Perron was a healthy scratch for only one game. … Washington is the 19th active franchise to win the Stanley Cup. The Caps were tied for the fifth-longest active Cup drought with Philadelphia, which won it in 1974. … Ovechkin has 26 points in 26 potential series-clinching games in his career