For Cooper, the streak is over.
The Hawks, who hadn't lost a regular-season game since the finale in 2016, fell 41-13 to Irondale on Wednesday night, a performance that Irondale coach Ben Fuller called a "one out of 10 chance" to put away a good team like Cooper.
With the game tied 13-13 at halftime, the host Knights (6-2) scored four second-half touchdowns en route to victory.
"We've been flirting with being this team all year long," Fuller said. "So I think that the guys bought into keeping that faith and preparing this week."
Cooper (7-1), ranked ninth this week in the Star Tribune's Metro Top 10, scored on the fourth play from scrimmage 1:06 into the game with a 55-yard pass play. But the Hawks, who scored their season low for points, went three-and-out three times in the second half.
Irondale senior running back Parker Freiberg scored on an 18-yard run on the first drive of the second half, putting the Knights ahead 20-13 and setting the tone for the rest of the game. Freiberg rushed for 240 yards.
"It was a defining moment for our team," Freiberg said. "We came into halftime and we said that we just had to keep going. We knew we could beat them."