Two of Virginia's best-known politicians, arch rivals since their bruising 1981 campaign, were back at center stage this week. It even had some people fantasizing about another race between the two in 1989.

There was Democratic Gov. Charles S. Robb in Washington, pressing a high-profile bid to turn his national party toward moderation.

Meanwhile, old foe J. Marshall Coleman of McLean, the Republican former state attorney general Robb defeated for governor in 1981, was in Richmond, surprising many with his decision to run for lieutenant governor in 1985, rather than governor again.

In a state where there is no political off-season -- there's an election every year -- oddsmakers quickly noted that should Coleman win in 1985, he would be in a prime position to run for governor in 1989. That's the same year that Robb, by law ineligible to succeed himself, could run again.

That would be an intriguing replay of the '81 contest in which the two candidates spent a total of about $5 million and established bonds of bitterness that still remain.

There are more immediate opportunities and problems for both young politicians. Many people in Richmond see Robb actually reaching for national office and Coleman simply trying to revive his stalled political career.

Coleman's lieutenant-governor decision is highly unusual and could hold the most pitfalls now. At 42, Coleman is still young, brash and eager to win statewide office again. Paradoxically, some say he runs the risk of looking too ambitious by running for lieutenant governor rather than governor, appearing willing to accept a lesser and safer role on the statewide GOP ticket rather than go for broke with the top spot again.

"I have no higher ambitions than to be lieutenant governor," Coleman joked with reporters Monday, showing the trademark wit that serves him well when asked difficult questions.

Coleman, a Washington lawyer, is not assured of the nomination. Several others, including state Sen. John Chichester of Fredericksburg and Del. A. R. "Pete" Geisen of Augusta County, are interested. None, however, is as well known as Coleman.

Coleman's decision leaves the GOP fight for the top spot to former Fairfax legislator Wyatt B. Durrette, now a Richmond lawyer, and Rep. Stan Parris, of Fairfax. They will have their first face-to-face appearance as candidates this weekend during a state party meeting in Staunton.

Coleman claimed to have a committee of 3,500 persons ready to work for his nomination for governor at the party's May 31 convention in Norfolk. His challenge now, some say, is to see whether they'll work just as hard for the second spot.

Robb, heading into the last year of his four-year term, has different problems, some of which he has little control over.

As chairman of the 35-member Democratic Governors' Association, Robb is a leader in the search for a new chairman of the Democratic National Committee. Robb and a number of other elected officials say the post should to go to a moderate who will speak to the nation as a whole rather than the party's collection of interest groups.

In the midst of the maneuvering, Robb lunched with reporters in Washington Monday, playing down but not rejecting suggestions that he may run for the U.S. Senate in 1988, for governor in 1989, or try for a spot on the presidential ticket in 1988.

But even as Robb focuses on the national party and his image, some say the state party that he is credited with reviving in 1981 is heading into perilous waters that may dampen that reputation.

Already, Robb is faulted by many in Virginia for not leading his state party to victory in Senate campaigns in 1982 and again this fall.

With three Democratic candidates vying to succeed him as governor, Robb is officially staying out of the early jockeying. He also has had little to say about the controversial lieutenant governor campaign of state Sen. L. Douglas Wilder of Richmond, the first black candidate of a major party to run statewide.

Some Democrats have expressed concern that Wilder's candidacy could hurt the entire ticket next year, and others are worried about the apparent willingness of the party to break even more new ground by nominating Del. Mary Sue Terry (D-Patrick) as the first woman candidate for attorney general.

A big Republican win, some Democrats warn, could take more than a little glow off Robb's emerging image as a leader of the party moderates' bold move to control the national party.