Dominic Pileggi didn't become one of the most powerful politicians in Pennsylvania by losing elections, and he wasn't about to start Tuesday in the first primary he'd faced in a decade.

Pileggi, 54, the state Senate majority leader and former mayor of Chester, had a large lead Tuesday night over tea party Republican Roger Howard in the Ninth Senatorial District, which stretches from eastern Delaware County past Oxford in Chester County.

Howard, 66, a free-market advocate with a doctorate in organic chemistry, had campaigned on a platform of cutting taxes, reducing government spending, and repealing the state's prevailing-wage law. He ripped Harrisburg Republicans as failing to pursue a fiscally conservative agenda following the party's success in 2010.

But Howard, of East Marlborough, Chester County, didn't stand a chance against Pileggi, a moderate Republican with a seven-figure campaign war chest and the backing of the GOP establishment in both counties.

Pileggi, a Chester City native who has served on its council and school board, was elected to the state Senate in a 2002 special election and became majority leader in 2006. This year, he had touted his support for increased government transparency by moving the state's open-records bill through the Senate.

In November, Pileggi will face Democrat Pat Worrell, a Chester resident and chairwoman of Action United, an advocacy group for low- and moderate-income Pennsylvanians.

Contact William Bender at 215-854-5255 or benderw@phillynews.com, or follow on Twitter @wbender99. Read his blog, "The Daily Delco," at www.philly.com/dailydelco.