GREENWICH, London — Butler boxer Brian Minto accepted a heavyweight fight on short notice and lost by a third-round knockout to undefeated Dillian Whyte Saturday night in the United Kingdom.

The 27-year-old Whyte (16-0, 13 KO’s) has stopped each of his last 12 opponents in four rounds or less. The 40-year-old Minto (41-10) was 30 pounds lighter and five inches shorter than Whyte.

Minto was dropped by a straight right hand at the end of the first round. He rebounded to land some right hands of his own in Round 2 while taking more punishment. Early in the third round, a right and two lefts floored Minto, who stayed on his knees while the referee counted him out.

The bout was for the vacant WBC International Silver Heavyweight title.