Curtis Stevens had to settle for a points win over the dogged James De La Rosa, despite making a brutal start.
The hard-hitting Brooklyn middleweight floored his opponent in the first round but failed to find the finish and had to settle for a unanimous decision over 10 rounds in the T-Mobile Arena, on Saturday night.
Stevens looked like making short work of it, around 30 seconds from the end of the first, as a typical hard left hook, had De la Rosa down in the corner.
He made the count and somehow survived an immediate onslaught reaching the bell after a barrage of bodyshots had him in more trouble.
Stevens' accurate punches then saw a cut open under De la Rosa's left eye in the second, and with him working just as well on the inside, it looked as if he would be move to 29-5 with 22 of those coming via stoppage.
De La Rosa though was not there to make up the numbers ahead of the Sergey Kovalev-Andre Ward bill-topper and the fourth and fifth rounds saw him start to push Stevens back.
The Mexican-born Texan came right back into contention as Stevens seemed to slow, his jab and his wide but accurate hooks, were now being matched.
Indeed in the eighth Stevens was deducted a point for a low blow and by the ninth he was clearly cursing in his corner at the end of the round, possibly due to a hand injury picked up early on.
De La Rosa had the audacity to throw his hands in the air, celebrating, midway through the 10th but Stevens, who took Gennady Golovkin eight rounds back in 2013, won by 98-90, 96-92, 96-92.