Three-plus extra pounds didn’t do Juan Carlos Abreu any good against this beast.

Welterweight contender Jaron Ennis put the rugged, but overmatched Dominican down three times and stopped him in the sixth round of a scheduled 10-round fight on the Erickson Lubin-Terrell Gausha card Saturday in Uncasville, Conn.

Abreu, who weighed in 3.2 pounds over the limit, had never been stopped even though he has faced a number of elite opponents.

Ennis (26-0, 24 KOs) now has 16 consecutive knockouts.

The quick, smooth, powerful Philadelphian came out firing at the opening bell, never really giving Abreu (23-6-1, 21 KOs) a chance to get anything going.

Ennis fought behind his jab, setting up one big power shot after another to all parts of Abreu’s body, and his movement and reflexes made him an elusive target.

Abreu, perhaps getting desperate, tried to get rough with Ennis in the fifth round but even that backfired, as Ennis still landed the more-damaging blows.

In the final seconds of that round, Ennis landed the punch of the fight — a counter right uppercut that put Abreu flat on his back and hurt him. He was able to get up and hear the bell to end the round but was in serious trouble.

Only seconds into Round 6, Ennis put Abreu down again with a right hand. He got up once more but the end was near. Ennis, a strong finisher, let loose his arsenal and knocked Abreu down one more time as the result of a combination of punches.

This tie, referee Johnny Callas stopped the fight without counting. The official time of 1:06.