Former state senator Howard A. Denis yesterday won the Republican nomination in the special election to succeed departing Montgomery County Council member Betty Ann Krahnke after he increased his lead over his closest rival in a tally of absentee ballots.

Denis led Mary Kane by 35 votes after Tuesday's primary, but more than 400 absentee ballots had not been counted. Once election officials had completed the day-long tally of those ballots last night, Denis had defeated Kane by 138 votes and county election officials said there are not enough pending overseas ballots to change the result.

"We have won the battle, and now the war starts," said Denis, after pacing in the Council Office Building for 90 minutes waiting for results. "It's going to be a vigorous, high-level race."

The drawn-out conclusion to the Republican contest to succeed Krahnke, who is suffering from Lou Gehrig's disease, begins a sprint to the April 18 election. Denis will face Democrat Patricia S. Baptiste for the Council District 1 seat representing Chevy Chase, Bethesda and Potomac on the nine-member council.

Baptiste, 58, easily won the Democratic contest on Tuesday after outpacing Washington lawyer Roger Berliner by 21 percentage points. But her race turned bitter in the closing weeks, and Baptiste has been reaching out to Democratic leaders since the primary in an effort to unite the party for the coming campaign.

The Republican race was far more amiable, and Kane was quick to congratulate Denis last night and pledged to support his candidacy. Moments after the two candidates were handed a computer printout of election results, Kane turned to Denis with her hand extended. Denis called the first-time candidate "a rising star."

"It's important to keep this seat Republican, and we are more than willing to help Mr. Denis do that," said Kane, 38, who ran GOP presidential candidate George W. Bush's Montgomery operation. "We'll be back."

Despite her party affiliation, Baptiste has been endorsed by Krahnke, a Republican. Registered Democrats outnumber Republicans in the district by almost 2 to 1.

Baptiste plans to emphasize the same themes she did in her successful primary campaign, particularly controlling growth in a district where some neighborhoods are suffering the symptoms of overdevelopment.

Denis, 60, has had a place on most county ballots since 1974. He ran a campaign long on shoe leather and personal gusto that stressed his experience in public office. He signaled that he would emphasize education and transportation in the general election.

Denis favors construction of the intercounty connector, for example, while Baptiste opposes the project. The $1 billion highway would connect Interstate 270 and I-95 north of the Capital Beltway, but Gov. Parris N. Glendening (D) withdrew his support for the project last year. A council majority opposes the project.

One possible key to the election will be voter turnout, since no other contest will share the ballot that day. Denis said he was relieved to be advancing to the next stage.

"I thought this was either my last hurrah or it would be a new lease on my public life," he said.