McWilliams Arroyo (17-3, 14 KO) outboxed and upset Carlos Cuadras (36-3-1, 27 KO) over 10 rounds as a part of the SuperFly 2 tripleheader on HBO, overcoming poor scorecards from the network’s unofficial scorer, prominant journalists and, worst of all, the official judges, settling for a majority-decision victory.

“I was very happy with my performance,” Arroyo said after the fight. “People underestimate me because I’ve been off for two years but I’ve been in the gym the entire time training. I knew I’d be victorious.”

Round 1 opened up and so did Arroyo’s blistering left hook. Cuadras returned some light combination punching but couldn’t score anything significant.

The Mexican did shake up Arroyo in the final minute of the second stanza with a right hand. Arroyo found himself doing his best to clinch up with his man to close out the period.

Arroyo’s Cleto Reyes gloves were back to work in Round 3, plugging one-twos followed up stiff uppercuts into Cuadras whose feet at least remained active throughout the fight.

The action swelled in the middle rounds. Each man’s chin was on display in sixth and seventh rounds.

The seventh stanza saw Cuadras sucking on air as Arroyo’s jab began to score points. The Puerto Rican closed the distance and reeled off combos into Cuadras who flung a wild left hand that missed the mark and left him off balance.

Arroyo, a former Olympian, picked up the pace in Round 8, interchanging right and left hooks off Cuadras’ temples. The Mexican was leaning over with his hands down, attempting to keep his feet wet, but only looked sloppy when firing counter  punches from his hip.

The tenth and final round was nothing special. But Arroyo remained sharp and supremely confident. He flashed a grin and darted in with some fine up jabs to close the show.

HBO’s unofficial scorer Harold Lederman, somehow scored the bout a draw. And ESPN’s Dan Rafael only found two rounds to give to the Puerto Rican.

Fortunately, two corners of the ringside judges actually watched the fight and gave Arroyo what he deserved.

The performance even impressed Cuadras’ trainer Abel Sanchez.

“Arroyo fought a very smart fight,” said Sanchez, who also trains middleweight superstar Gennady Golovkin. “He never let Cuadras do anything.”

A two-time title challenger at 112 pounds, Arroyo successfully moved up in weight to the super flyweight division.

Cuadras is a real fighter, a former champion whose only previous losses were to pound-for-pound claimants Roman “Chocolatito” Gonzalez and Juan Francisco Estrada. The Mexican also holds a win over Srisaket Sor Rungvisai.

Per CompuBox, Arroyo outlanded his opponent in total punches (20 percent to Cuadras’ 16 percent) and power punches (107/415) for a connection rate of 26 percent, compared to 19 percent for Cuadras (87/458).

Arroyo, whose brother McJoe is a former super flyweight champion himself, is now next in line for the WBC 115-pound crown up for grabs between Srisaket Sor Rungvisai and Juan Francisco Estrada at the top of the bill.

“I’m ready for the winner of the main event,” Arroyo said. “I’m the best fighter in the division.”