LAS VEGAS – Eduardo Ramirez left no doubt about his rematch with Leduan Barthelemy.

The aggressive, determined Mexican dropped Barthelemy with a right-left combination in the fourth round of their 10-round rematch Saturday night at MGM Grand Garden Arena. The featherweight contender got full extension on his straight left hand, which sent Barthelemy stumbling backward and to the canvas.

Barthelemy answered referee Russell Mora’s count in time. Once he turned his back on Mora and Ramirez, Mora stopped their fight with one second remaining in the fourth round on the Deontay Wilder-Luis Ortiz undercard.