In one of the most competitive races in years for Washington County's top law enforcement post, Republican newcomer Steven M. Toprani scored a stunning victory over embattled District Attorney John C. Pettit.

The race that promised to be the most exciting in the county last night did not disappoint, with Mr. Toprani, 28, of Carroll, running away with a 2-1 lead over Mr. Pettit, 72, of Washington, for most of the night.

A Democrat seeking his seventh and final term, Mr. Pettit for the first time invested in television commercials and a Web site, and focused his attacks on Mr. Toprani's age and lack of experience. Mr. Toprani has never tried a case before a jury, but has worked in state government and his own practice since becoming a lawyer two years ago.

Mr. Toprani enjoyed the support of much of the county Democratic Party, which held joint fund-raisers for him with the local GOP.

Local Democrats said they were tired of the county's reputation of corruption and some members had a falling out over party donations with Mr. Pettit, who has been the subject of an FBI probe and received criticism for his actions, including the use of questionable witnesses in murder trials.

Mr. Toprani said last night he expected the race to be closer, and was thankful.

"It's tremendous -- I don't know what to think. I'm very, very humbled and proud of this. We took our message of change to the voters and they believed we could make Washington County a safer place."

The county, with a 2.2 to 1 Democratic voter registration edge, had not elected a Republican to the post since 1963.

In the race for the county's three-member board of commissioners, incumbent Democrats J. Bracken Burns and Larry Maggi, along with incumbent Republican Commissioner Diana Irey, held tight to a slim lead over Republican challenger Mike Neville of Peters.

Mr. Burns, 62, of South Strabane, and Mrs. Irey, 45, of Carroll, were seeking their fourth term, while Mr. Maggi, 56, of Buffalo, was running for his second term.

Mr. Neville, 47, a former Peters councilman, was critical of commissioners for a property tax hike in 2004 and said he would work to rescind a 3 percent annual raise commissioners voted for themselves and county employees several years ago. Mr. Neville supported a pay increase for county workers, but not for commissioners.

In the contest for register of wills, Democratic Deputy Register of Wills Mary Jo Poknis, 52, of Fallowfield, appeared to beat Republican Lynette Leasure, 48, a longtime US Airways customer service agent from Cecil. Current Register of Wills Kathleen Flynn Reda is retiring.

In a heated battle for prothonotary, three-term incumbent Phyllis Ranko Matheny narrowly led challenger Judith Fisher, the county's Democratic jury commissioner.

Ms. Matheny, 66, of North Strabane, won re-election four years ago by only seven votes as a GOP write-in, even though she lost the Democratic primary to Mrs. Fisher, 68, of South Strabane.

This time, Ms. Matheny again fell to Ms. Fisher in the primary -- by 29 write-in votes -- but secured the Republican nod.

Common Pleas Judge Paul Pozonsky, 52, of Cecil, won a second 10-year term.