Baltimore Mayor William Donald Schaefer's campaign for governor started about 60 days earlier than he had planned last week when he was pushed into verbal combat with the man who is expected to be his chief opponent in the Democratic primary, Maryland Attorney General Stephen H. Sachs.

Schaefer hasn't declared as a candidate, but has told countless numbers of supporters throughout the state that he has every intention of running this year. Keeping to that strategy, he had refused to engage in debate, leaving Sachs punching at empty air.

The attorney general has accused the mayor of cronyism and secret dealing, and Schaefer has shrugged the accusations away.

But last week, the scenario began to change when Sachs, the state's top law enforcement officer, accused Schaefer, the mayor of a city seemingly awash in handgun crime, of waffling on the controversial issue of gun control.

A few days earlier, Sachs, Lt. Gov. J. Joseph Curran and Baltimore State's Attorney Kurt Schmoke had praised a bill then pending in the Senate that would have given the city its own gun control powers.

Schaefer did not speak publicly on the issue until, pressed by a group of Salisbury businessmen, he said he found the bill "simplistic" and "a political gimmick."

The gun bill failed in Annapolis, killed at the hand of a committee chairman who is an ardent Schaefer backer, and the debate over the issue started to die out.

But Saturday, Schaefer was dragged into the political arena again in a confrontation with Sachs at a Democratic dinner in Carroll County attended by other top state officials, including Gov. Harry Hughes.

Throughout the room, Sachs supporters wearing blue and yellow campaign buttons stomped, clapped and whistled when Sachs was called on to make remarks. Schaefer folded his arms tightly and lowered his chin to his chest.

"I've been told the purpose of this event is unity," Sachs said. "I want unity. Unity, however, in November doesn't mean silence in March."

The air in the room turned uneasy. The governor blinked. The mayor glowered just a bit. Carroll County Democrats still digesting their roast beef shifted in their chairs stiffly.

Sachs talked of cronyism and a clash of political philosophies -- the two issues he has tried in vain to use as brickbats against the popular Schaefer.

Schaefer was applauded enthusiastically when he rose to speak, marveling aloud that he had somehow stumbled into a political event.

"I walked in the door and someone slapped a blue and yellow button on me," he related. "The people said, 'I'm for Sachs.' I said, 'Who's he?' "

Then he delivered his familiar road speech, speaking of how he has worked with local officials, conferred with Western Maryland Rep. Beverly Byron about the effect of the Gramm-Rudman federal deficit reduction legislation and increased tourism revenues for the state by rebuilding Baltimore.

"I've been branded with 'He only knows Baltimore,' " Schaefer said in a thinly veiled reference to Sachs' television advertisements. "Now you know that's not true."

Sachs, he indicated, should not be the only one to define what issues are debated. The attorney general's role in the state's savings and loan crisis should also be part of that discussion, he said, along with what he described as Sachs' antibusiness reputation.

"If we're going to talk about them, let's talk about them all," he said.

This time it was Sachs' turn to sit with a tight smile on hs face.

And Schaefer went on. Debates, he said, just make the guy whose makeup is more artfully applied look good. Sachs has been campaigning for three years while Schaefer has been running the city, he declared. A good business climate means jobs, he said, implying that Sachs' record as a tight regulator of business dampens that climate.

Then he caught himself. "I didn't know we were going to have a debate tonight," he said.

But the debate, it seems, has begun.