Winning their respective parties' primaries Tuesday by large margins, Democratic City Councilman Michael McMahon and former Republican Assemblyman Robert Straniere will compete in Staten Island in November for the city's last remaining Republican congressional seat.

With all 523 precincts reporting, McMahon won 75 percent of Democrats' votes, beating lawyer Steve Harrison by a 50-point margin.

With all precincts reporting in the Republican primary, Straniere won 59 percent of the Republican vote, defeating Staten Island G.O.P. finance chairman Dr. Jamshad Wyne, who received 41 percent.

The hotly-contested seat, which covers Staten Island and parts of Brooklyn, is being vacated by Representative Vito Fossella, who chose not to run again when it was discovered that the married father of three had a child with another woman.

After his victory, McMahon, who had the support of party bosses, thanked his supporters and said he would not let them down.

"I make you a promise tonight, my friends," said McMahon. I make promise to continue to earn that trust that has been afforded me this evening, by bringing our fight all the way to Washington. To work for the change that all of you deserve for this district."

Earlier Tuesday, Straniere was doing last-minute stumping in the Staten Island ferry terminal but was confident of his victory.

"People like our positive message, the way we have run our campaign on the issues, talking about tax cuts, talking about energy independence," said Straniere.

In Manhattan, powerful New York State Assembly Speaker Sheldon Silver emerged victorious in his first primary challenge since the 1980s.

Silver won 68 percent of the vote, with 23 percent won by non-profit consultant Paul Newell, who was endorsed by the New York Times, the Post, and the Daily News. Attorney Luke Henry's received 9 percent of the vote.

Earlier Tuesday Silver said he believes his record over the last three decades stands for itself.

"I have done health care, education for the people in this district, and I believe that they will come out and show that they are supportive of that," said Silver, who has the support of the two New York senators.

Silver's opponents said during their campaigns that the longtime incumbent is entrenched and out of touch, and noted how he never debated with the other Democratic candidates.

After his victory Tuesday night, Silver thanked his loyal constituents.

"This campaign was about real people with real needs. Not about tabloid headlines," said Silver.

Two of three politicians endorsed by Mayor Michael Bloomberg won their respective primary elections.

Novice 28-year-old challenger Daniel Squadron won 56 percent to the 46 percent earned by longtime Manhattan State Senator Martin Connor, who first entered the state Legislature about two more years before Squadron was born.

In Upper Manhattan, Assemblyman Adriano Espaillat maintained his incumbency, winning nearly 54 percent to City Councilman Miguel Martinez's 46 percent.

Only Bloomberg-approved Brooklyn Councilman Simcha Felder lost in a three-way race to unseat State Senator Kevin Parker, who earned 49 percent of the vote.

In Brooklyn, Congressman Edolphus Towns won 68 percent of his primary's votes, defeating the 32 percent earned by Kevin Powell, a writer, activist and former cast member of MTV's "Real World."

In a bitterly-contested race in Queens for a Flushing State Assembly seat, Grace Meng beat out Ellen Young in the primary, 59 to 41 percent.

Bronx State Senator Efrain Gonzalez, who earned 40 percent of votes, lost the party nod to 60 percent won by challenger Pedro Espada, Jr. Gonzalez was under investigation for stealing money from a local children's charity.