In a bout four years in the making, the pair of lightweight stars met for all the marbles in Las Vegas.
And it was about as highly competitive as 12 rounds of boxing can be, leaving fans and pundits almost unable to split them.
But all three judges disagreed as Haney emerged with a unanimous points win and his WBC, WBA, IBF and WBO belts to go with it.
He said: “I take my hat off to Loma, future Hall of Famer, he was my toughest opponent by far, he’s very crafty.”
Haney, 24, came out attacking the body from the get-go but Lomachenko, 35, was quick out the traps too.
And he proved his famed footwork showed no signs of losing a touch as the Ukrainian at times danced around the American.
Haney was the one leading off in the opening stages, pumping out a stiff jab but Lomachenko was quick to counter in combinations.
Any time the champion did land something of note, he was met with a return, making for great action in the centre of the ring.
Haney favoured the double jab and right hand to the body through the mid stages of the bout, causing reddening around Lomachenko’s body.
But the night’s challenger kept Haney in check with a couple of beautiful left hands snapping his head back.
Towards the last third of the bout, Lomachenko came on strong, setting up flurries of combinations that Haney struggled to defend.
It appeared to be too close to call heading into the final three minutes, where it was all to play for.
But Haney showed his champion’s status by coming out strong and wrestling back the momentum.
The final round fightback proved the difference on the deciding scorecards and enough to edge out the result.
But a fuming Lomachenko – who was left in tears backstage – did not agree as he was left speechless with the decision.
He said: “I don’t want to talk about this. All people see what happened today.
“I can’t talk about this right now, it’s just not a comfortable moment for me.”
Haney – who was BOOED by his home Vegas crowd following the win – has teased a move up in weight ever since winning his belts but his future remains undecided.
He said: “It’s always been tough for me to make the weight and I’ve accomplished everything at 135.
“I just beat a future Hall of Famer, this is my eighth title defence, so we’ve just got to see.
“But there’s a lot of great fighters at the 135lb division so we’ll see.”