Businessman Bob Dold won the Republican nomination in Illinois’ 10th district on Tuesday and will face marketing consultant Dan Seals (D) in the race to succeed Rep. Mark Kirk (R) in November.

Dold led the GOP field with 39 percent. His closest rival, state Rep. Beth Coulson, had 30 percent and she conceded the race at 10:30 p.m.

On the Democratic side, Seals eked out a win of 48 percent to 47 percent over state Rep. Julie Hamos — a margin of victory that amounted to about 658 votes. Despite the small margin, Hamos called Seals to concede.

Seals was the 2006 and 2008 nominee against Kirk in the district. The November race is expected to be a top target of both parties, and it is also likely to be an expensive contest since the North Shore district is entirely within the Chicago media market.