Democrats received some good news tonight, as former Microsoft executive Suzan DelBene (D) advanced to the general election in the top-two primary for Washington state’s open 1st district.

DelBene, who self-funded her primary campaign, will have the early edge in the general election against Snohomish County Councilman John Koster (R).

The Associated Press called the race with 41 percent of precincts reporting. Koster led with 44 percent, followed by DelBene with 23 percent. Behind them were three Democrats: former Microsoft manager Darcy Burner with 15 percent, former state Rep. Laura Ruderman with 7 percent and state Sen. Steve Hobbs with 7 percent.

Koster and DelBene are both looking to win after defeats in different Congressional districts in 2010. Koster lost to Rep. Rick Larsen (D) in the 2nd district, and DelBene lost to Rep. Dave Reichert (R) in the 8th district.

As the lone Republican running, Koster was expected to make it out of the top-two primary. DelBene was in a battle in the closing weeks with several other Democrats for second place, but her personal infusion of $1.9 million into her campaign allowed DelBene to spend more on TV ads and direct mail than any of her opponents.

Republicans were hoping Burner, a liberal darling, would advance, making the divided district more difficult for Democrats in a presidential cycle. Even with DelBene, the district’s makeup means the GOP likely won’t be writing the seat off just yet.

A bipartisan commission drew the lines after it became clear former Rep. Jay Inslee (D) would vacate the seat to run for governor, and the 1st is now the most competitive in the state. It’s split between the Democratic-leaning Seattle suburbs, which include the Microsoft campus, and a Republican-leaning agricultural area in three large counties to the north.

In other general election matchups of note decided tonight: Sen. Maria Cantwell (D) is heavily favored over state Sen. Michael Baumgartner (R); former state Rep. Denny Heck (D) is heavily favored over Pierce County Councilor Dick Muri (R) in the new 10th district; and in the 6th district race to replace retiring Rep. Norm Dicks (D), state Sen. Derek Kilmer (D) and businessman Bill Driscoll (R) appeared headed for the general, in which Kilmer will have the edge.