Watch out for the Nation's Capital to muscle in on all that "City of Champions" biz in the 1980s, even if some of the championship-deciding events have to be imported.

That's pretty much the theme of the Greater Washington Sports Authority unveiled yesterday by Mayor Marion S. Barry Jr. in his District Building offices -- and if you think the NBA All-sTar Game and Soccer Bowl '80 coming up in Capital Centra and RFK Stadium, respectively, are the tops, you ain't seen nothin' yet.

The authority, 18 members with banker Joseph H. Riley as president, will be going after big stuff, according to Riley, Barry and colleagues from the commercial and public sectors of the metropolitan area. For instance, the Army-Navy game and other major college football; championship fights (no importing necessary here, if Sugar Ray Leonard and cohorts are willing); international soccer (NASL Commissioner Phil Woosnam was on hand to encourage "mid-'80s" visions of World Cup play in the U.S.A.).

Barry expressed pride in having wooed the NASL title game here on a New York visit that swept the league off its feet, and now Riley has organized a committee to coordinate events connected with that Sept. 21 contest.

Some of the GWSA members include Walter Fauntroy, Jack Herrity, Lynda Robb and Steve Danzansky -- more vitally interested than most, what with his soccer Diplomats having so much at stake, and with the example to follow, of promoting sports in Washington as a catalyst to economic development and civic goodwill, set by his late father, Joe Danzansky.

A baseball team? They'll try . . .

The pro football trend toward wider-open, more aerial-minded offenses no doubt got a fresh boost yesterday with the Denver Broncos hiring Rod Dowhower as offensive coordinator. Dowhower leaves after one year as head coach at Stanford, where the "1" in his 5-5-1 record was the 21-21 tie with Southern California that probably cost USC the national title. Stanford was a throwin' bunch under this fellow -- and naturally; he coached passers, receivers and ultimately co-ordinated the whole offense under Don Coryell when the current Charger pass-master had San Diego State flinging it all over . . . .

Caught by surprise by Dowhower's resignation, Stanford now starts scrambling for a successor . . . Georgia Tech has a football coach, Bill Curry, hired this month, but now needs an athletic director to replace Doug Weaver, off to Michigan State. Weaver, taking over as a.d. in East Lansing, says he conceivably could have a football coach for the Spartans within a week; but don't rush him . . . h

On the Brooklyn side:

"They all fought there -- Patterson, Marciano," lamented erst-while middleweight boxer Dee Berry, 45. "It was beautiful, just beautiful." It was Eastern Parkway Arena, a stepping stone to the Garden for comers, Valhalla for just plain pugs, and it has burned down, gutted by a "suspicious" three-alarmer.