Mariusz Wach stopped Tye Fields in the sixth round and retained his WBC international heavyweight title.
Wach (27-0, 15 KOs) won by knockout on Saturday and was never seriously hurt by Fields.
Wach unloaded a series of lefts and rights at the head and sent Fields into the ropes and face first onto the canvas. Fields (49-5) made it to his knees but could not get up at 1:44 of the round.
Wach had hundreds of Polish fans cheering him on at Resorts Hotel and Casino. Wach, out of Krakow, now lives in New Jersey.
After a methodical first four rounds, Fields took a beating in the fifth. Wach targeted Fields face for most of the fight, bloodied his nose and left him staggering in the fifth.
The 6-foot-7 Wach won his seventh straight bout by knockout or TKO.