LAS VEGAS – Austin “Ammo” Williams remained unbeaten Saturday, but he had much more trouble with Kieron Conway than he predicted.

Williams was dismissive of Conway during a press conference Thursday, when he promised a demolition similar to his first-round stoppage or previously unbeaten Chordale Booker in his previous fight. Conway was much tougher than Williams believed, however, and took the hard-hitting middleweight prospect the 10-round distance for the first time in his three-year career.

Milwaukee’s Williams won a unanimous decision in the first fight of the pay-per-view portion of the Canelo Alvarez-Gennadiy Golovkin undercard at T-Mobile Arena. Judges Chris Migliore (97-92), David Sutherland (97-92) and Steve Weisfeld (96-93) scored their fight for Williams, who took over during the final few rounds against a bloodied, fatigued Conway.

Williams improved to 12-0 (8 KOs). England’s Conway, who has never been knocked out, fell to 18-3-1 (4 KOs).

Conway spent most of the 10th round trying to survive after Williams dropped him in the ninth round. By then, Williams was in control of a fight that was very competitive in the earlier rounds.

A right uppercut by Williams sent Conway to the canvas with just over 1:20 to go in the ninth round. Conway was bleeding from his mouth, but he beat referee Robert Hoyle’s count and made it to the end of the ninth round.

Hoyle called for a brief break in the action with 1:43 to go in the eighth round, so that Conway’s handlers could re-tape his glove. Williams was the aggressor throughout the eighth round, but Conway moved and held enough to avoid taking many clean shots in those three minutes.

A left hand by Williams made Conway hold him approximately 45 seconds into the seventh round. Another left hand by Williams got Conway’s attention with about 1:20 to go in the seventh round.

A right hand by Conway backed up Williams with just over a minute to go in the sixth round. Williams mostly had trouble again in the sixth round finding Conway with left hands.

Williams caught Conway with a straight left barely a minute into the fifth round. Another left hand by Williams knocked Conway off balance with about 45 seconds to go in the fifth round.

Conway caught Williams with a short right on the inside with about 30 seconds to go in the fourth round. Williams had difficulty during that round landing clean punches on Conway.

A right hand by Conway backed up Williams with just under 1:20 on the clock in the third round. Williams landed a left hand as he backed Conway into a corner toward the end of the third round, but Conway came back with a right hand.

After Williams and Conway spent most of the first round feeling each other out, the action picked up in the second round.

Conway connected with a straight right hand just after the midway mark of the second round. Williams snuck in a left hand just before the end of the second round.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.