One more title Alexander Mikhailovich Ovechkin cemented last week: greatest professional team sport player in Washington history. Ever.

I reached the surety of making that declaration in a moment of clarity, and not in the rapturous vapors of euphoria wafting through the D.C. area in the wake of Ovechkin finally leading the Capitals to the Stanley Cup.

It wasn’t easy. Just read Darrell Green’s biography in the Pro Football Hall of Fame. The speedy cornerback, who played all 20 of his NFL seasons with RFK Stadium (where I was reared in Section 312) and FedEx Field as his homes, was a seven-time Pro Bowl selection. He helped lead his team to four NFC championship games, three Super Bowls and two NFL titles, often in spectacular fashion. His punt return for a touchdown in the second half of a divisional playoff game in January 1988 to lead a comeback against the Bears in Chicago, on which he ran much of it clutching his midsection after tearing rib cartilage leaping a would-be tackler, was instantly iconic. Yet Green wasn’t the greatest of his generation at his position. Ovechkin is.

This past season, Ovechkin was selected to his ninth NHL All-Star Game. He led the league in goals scored for the seventh time in his 13 seasons, which surpassed everyone in NHL history in that short a time frame to start a career except Bobby Hull, who led the league in goals seven times in his first 12 seasons, the last time almost half a century ago.

This season, Ovechkin became the fourth-fastest NHL player to 600 goals. The only players to reach the mark faster were Wayne Gretzky — the greatest goal scorer in NHL history — Mario Lemieux and Brett Hull.

And it was easier to score goals when Gretzky electrified the league and Lemieux and Brett Hull tried to catch up. Goals a game per team hovered around four in the 1980s. In Ovechkin’s era, they’ve dropped below three. Defenses have tightened up. Goalies have gotten bigger physically and have been allowed to wear bulkier padding. Nonetheless, Ovechkin has excelled.

The statistical site noted in April: “From 1987 to 2018, Ovechkin has earned more point shares than any other player through their age-32 season.” In other words, for the past 30 years, no one has created more goals. That includes his nemesis, and ours, Sidney Crosby in Pittsburgh.

Ovechkin didn’t become our first team athlete to be so dominant in his or her generation. When I first uttered my thoughts on Ovechkin via tweet Saturday, a number of people countered with the Senators’ World Series-winning pitcher Walter Johnson and quarterback Sammy Baugh, who led Washington to two NFL championships.

Johnson was among the first five electees to the Baseball Hall of Fame in 1936. No one has ever thrown more shutouts in baseball history. Only Cy Young won more games. Johnson’s career strikeouts record stood for more than half a century. He even gave Washington its only World Series title in 1924.

But Johnson played his 21 big league seasons, all in Washington, during the 60-year stretch when baseball refused to let black men participate. He didn’t play against the best, and, sadly, neither did those who starred in the Negro leagues such as Josh Gibson, the legendary slugger for the Homestead Grays, who played half of their games in the 1940s in D.C.’s old Griffith Stadium.

Baugh played all sides of football for our NFL franchise when its home was Griffith Stadium. He was a quarterback who burst onto the scene as a rookie in 1937, when he threw for 335 yards in Washington’s NFL championship game victory over the Bears. That total remained unsurpassed by a rookie in any playoff game until Seattle’s Russell Wilson topped it in January 2013. In between, Baugh registered exploits such as throwing for four touchdowns and intercepting four passes in a win over Detroit in 1943. That season, he led the league in passing, interceptions and punting. He alone sparked this region’s fanaticism for football, not unlike Ovechkin has done for hockey.

But the first half of Baugh’s career was like all of Johnson’s. It came during the period in which the NFL decided to prevent black men from playing, an occurrence that came only after George Preston Marshall bought into the league with his purchase in 1932 of the league’s Boston franchise, renaming it in 1933 to its controversial nickname, moving it here in 1937 and keeping it the last all-white team until the federal government forced him to integrate it in 1962.

That Ovechkin led the Caps to the Stanley Cup 40 years to the day that the Washington Bullets won their only NBA title called to mind one other local-team athlete worthy of consideration: center Wes Unseld. Like Ovechkin, Unseld was a rookie of the year, but with the Bullets when they were based in Baltimore, and a league MVP, but in Baltimore. He did, however, lead the Washington Bulletsto two other NBA Finals they didn’t win.

When I was growing up, I thought Sonny Jurgensen was the be-all and end-all around here. I was just coming to consciousness as a sports fan when Jurgensen was setting all manner of passing records in the league despite playing with a losing team.

But Sonny never did what Ovi has done. No one has. And Ovi, fortunately for us, isn’t through.

My friends Mike Wilbon and Tony Kornheiser each have tales about proclaiming in the presence of the legendary sports columnist Shirley Povich the greatness of some Johnny-come-lately baseball player, only to be schooled by Povich suggesting them incorrect while recalling a conversation he had with Walter Johnson or Babe Ruth.

Povich lived to be 92 and was writing to the end. Should I last so long in this business, and some up-and-coming sportswriter proclaims the greatness of some whippersnapper athlete on a local team, I will school her or him with the retort, “Well, I watched Alexander Ovechkin . . .”

Our greatest.

Kevin B. Blackistone, ESPN panelist and visiting professor at the Philip Merrill College of Journalism at the University of Maryland, writes sports commentary for The Post.