Updated: 11:58 p.m.

Ohio Lt. Gov. Lee Fisher won the Democratic Senate nomination on Tuesday and will face former Rep. Rob Portman (R) in what is expected to be one of the most closely watched contests of the cycle.

Fisher defeated Ohio Secretary of State Jennifer Brunner 55 percent to 45 percent in the Democratic contest. Fisher outperformed Brunner in fundraising, had the support of Gov. Ted Strickland (D) and was the preferred candidate of the Democratic Senatorial Campaign Committee.

“Lee Fisher is focused on creating jobs, holding Wall Street accountable, and stopping the excesses of oil and insurance companies,” DSCC Chairman Bob Menendez (N.J.) said in a statement that also accused Portman, a former budget and trade official in the administration of President George W. Bush, of having “created the economic mess we are in.”

National Republican Senatorial Committee Chairman John Cornyn (Texas) said in his own statement that Fisher “was hand-picked by Washington Democrats because they know he will serve as another rubberstamp” for President Barack Obama and Senate Majority Leader Harry Reid’s (D-Nev.) “deeply unpopular agenda” if he is elected.

One of Fisher’s top priorities is to forge party unity with Brunner, who accused Fisher’s allies of trying to push her out of the primary, and to replenish his campaign fund to stay competitive with Portman, who had nearly $7 million more in the bank than Fisher as of mid-April.

The winner of the November contest will succeed retiring Sen. George Voinovich (R)

In House race results Tuesday night, businessman Jim Renacci won the Republican nomination in the Canton-based 16th district, where he’ll face freshman Rep. John Boccieri (D) this fall.

With about three-fourths of the GOP vote counted, Renacci led Matt Miller, a former county commissioner, 49 percent to 40 percent.

Renacci, a former small-city mayor, and Miller, who ran competitive but losing efforts in the 2006 and 2008 primaries, were close during most of the vote-counting, but Renacci pulled ahead after populous Stark County, which includes Canton, reported the bulk of its votes late Tuesday.

Renacci was the preferred candidate of the National Republican Congressional Committee, which is looking to reclaim the historically GOP-leaning district this November.

Republican officials think that Boccieri is vulnerable in part because of his votes for a health care overhaul and a climate change bill that called for a cap-and-trade system to reduce greenhouse gases.

Democrats see vulnerability in Renacci’s business operations and in his resistance several years ago to a tax assessment.

Elsewhere in the Buckeye Sate, the GOP primary in the 18th district remained too close to call just before midnight Tuesday. Fred Dailey, a former Ohio agriculture director and the 2008 nominee, and state Sen. Bob Gibbs, the NRCC’s favored candidate, were locked in a tight race that included six other candidates. The winner of the GOP contest will face Rep. Zack Space (D) in November in a race that national Republicans hope to target.