Newark Mayor Cory Booker won the Democratic primary in the New Jersey Senate race on Tuesday -- a victory that sets him on a clear course to become the newest U.S. senator.

With 98 percent of the precincts reporting, Booker was taking about 60 percent of the vote in a four-candidate field. Rep. Frank Pallone Jr. was second with 20 percent, while Rep. Rush D. Holt was at 17 percent and state Assembly Speaker Sheila Oliver was below 5 percent.

The victory propels Booker into the special election on Oct. 16 against former gubernatorial candidate and former Bogota mayor Steve Lonegan, who won the Republican nomination with about 80 percent of the vote.

The winner will complete the remaining 15 months of the term of the late Sen. Frank Lautenberg (D-N.J.), who died earlier this year. The seat will also be up in 2014.

The victory came as no surprise for Booker, who began his campaign with a huge advantage in the polls and high name recognition thanks to an aggressive media presence. Quinnipiac University's first Democratic primary poll found that almost three out of four voters had an opinion of Booker, most of which were positive. His opponents were unknown to more than two in three voters.

Well before this year's Senate race, Booker, 44, was seen as a fast-rising star in the Democratic Party, with some seeing him as a potential future presidential candidate.

In his victory speech, he stressed bipartisanship and optimism.

"I may have been born in that city (Washington, D.C.), but this state taught me a thing or two about hope and optimism," Booker said. "If I am your U.S. senator, the direction I am most concerned with will not be right or left but will be with going forward."

During the two-month primary, neither Pallone nor Holt was able to call into question Booker's fitness for the office or gain any momentum. Pallone was endorsed by Lautenberg's family and had more than $3 million in his House account when the Senate race started, but he never aggressively targeted Booker.

Booker quickly erased Pallone's financial advantage, pulling in $4.5 million in the second quarter while Pallone lagged far behind.

The election during summer vacation season was not expected to draw many voters to the polls but the combination of rain and Booker’s anticipated victory drew an exceptionally low turnout.

Lonegan has centered his campaign around opposition to President Obama and is expected to continue his criticism of the Affordable Care Act, which will go into effect two weeks before election. Lonegan ran in 2009 as the conservative GOP alternative to now-Gov. Chris Christie (R), losing in the primary.

Christie and Booker have forged a strong relationship, and Booker declined to challenge Christie in this year's gubernatorial race.

Christie appointed an interim senator after Lautenberg's death, Republican Jeff Chiesa, but Chiesa decided not to run in the special election and Republicans failed to land a top-tier recruit for the race.

In a fiery victory speech in Secaucus on Tuesday night, Lonegan blasted Booker as a candidate "anointed by Hollywood" and the top choice of "Silicon Valley moguls" who want to make him a third senator for California.

"We know what we believe in," he said. "We're going to say what we believe, and when we go to Washington, D.C., we are going to do what we say."

Despite his victory, Booker is likely to face continued questions over his business dealings. The New York Times raised questions in recent days about Booker's role in a technology start-up that has paid Booker handsomely and raised money from big-name donors despite having a very limited digital presence.

National Republicans are not expected to seriously contest the race, and polls show Booker leading Lonegan by a wide margin.

Updated at 11:30 p.m.