Zhilei Zhang scored the biggest win of his career Saturday in Riyadh, Saudi Arabia, and might have effectively ended former heavyweight champion Deontay Wilder’s in the process.

China’s Zhang, 41, connected with a perfectly timed counter right hook that spun Wilder in a daze. With Wilder defenseless, Zhang sprinted in and smashed him with another right hand that planted the American hard on the canvas.

Wilder, 38, somehow was on his feet before the count of 10, but his legs were unsteady as the referee wisely waved off the fight at 1:51 of Round 5.