Whoops.

An Oklahoma high school basketball player hit a dramatic buzzer beater in a state playoff game Thursday – for the other team.

Hugo HS guard Trey Johnson cost his team a Class 3A state quarterfinal game against Millwood when he laid the ball into his team’s own basket in the closing seconds. Hugo was up by one with 3.7 seconds remaining when Johnson caught the ball off an inbounds pass. And Millwood secured a 38-37 win over Hugo when Johnson, instead of running out the clock, scored in the wrong hoop.

“When I saw the kid going that way, I was like, ‘No, he’s not. No, he’s not … Oh, yes he is,’” Millwood assistant coach David Samilton told NewsOK.com. “I couldn’t believe it.”

No one else could either. The arena fell silent when the ball went through the rim. Then the Millwood fans erupted in celebration. Johnson will probably never be able to live it down.

mraimondi@nypost.com