Former Interior Secretary and Trump-backed Ryan Zinke won an unexpectedly tight race Thursday to become the Republican nominee in the race for a new U.S. House seat representing western Montana, a victory that comes after days of hand-counting ballots in one county.

Zinke’s win gives Trump an undefeated June 7th Primary run across Montana, California, South Dakota, and Iowa. All Trump-endorsed candidates won their primary races.

According to the Associated Press who called the race with 99% of the votes in, Zinke defeated former state Sen. Al “Doc” Olszewski by just over 1,600 votes out of 84,500 cast in the race, or 1.9 percentage points, according to preliminary numbers. Unofficial results had Zinke with 35,241 votes to 33,633 for Olszewski.

Zinke won “despite facing more than a million dollars of negative advertising against him” by three Republicans, two Democratic candidates, and a Democratic Super-PAC, his campaign said in a statement.

In a statement, Zinke thanked former President Donald Trump and others for their endorsements, as well as western Montana residents for their “confidence that America can be fixed and for ignoring” the political attacks.

Zinke’s win gave Donald Trump a 6/6 record for this week’s primary elections held on June 7th. Other Trump-endorsed winners included Governor Kristi Noem of South Dakota, Senator Chuck Grassley of Iowa, Governor Kim Reynolds of Iowa, U.S. Rep Ashley Hinson of Iowa, and U.S. Rep Kevin McCarthy of California.