By Lem Satterfield

WBC 154-pound champion Jermell Charlo’s 6-0 with five knockouts and a combined seven knockdowns against southpaws over the past nearly seven years.

“The Iron Man” flattened Chris Chatman to his back in March 2012 with a straight right for a one-punch, third-round TKO, Denis Doughlin was dropped and stopped in the fifth round in June 2012, and Jose Angel Rodriguez never fought again after Charlo battered him in October 2013 over the course of a 10th-round TKO victory.

Charlo’s first- and second- defenses were against left-handers in April and October 2017 at Barclays Center in Brooklyn, New York, where he twice floored Charles Hatley for a sixth-round KO, and once dropped previously unbeaten Erickson Lubin for for a first-round stoppage.

Hatley fell face-first and out cold on the canvas beneath a bottom rope from Charlo's head-swiveling right hand, and Lubin crashed to the canvas on his left leg from a head-lurching right uppercut, toppling over his right side, his left arm and leg flailing as the referee ended it.

Charlo’s last fight in June was a two-knockdown majority decision over left-handed former champion Austin Trout, but the 28-year-old Houston native trailed, 69-64, on all three judges’ cards in May 2016 against the last right-hander he faced before finishing John Jackson in the eighth of their vacant title fight.

Charlo (31-0, 21 KOs) meets his second orthodox fighter in five bouts in repeat title challenger Tony Harrison (27-2, 21 KOs) as "The Iron Man" pursues his fourth defense and third stoppage during that time on December 22 at Barclays Centeron FOX at 8 p.m. ET/5 p.m. PT.

Charlo-Harrison is the co-main event to older-by-a-minute twin sibling, Jermall (27-0, 21 KOs), who is chasing his initial defense, fourth consecutive stoppage and 20th knockout in his past 22 bouts against third-time title challenging southpaw Willie Monroe (23-3, 6 KOs).

“Tony’s punching power will be a difference from John Jackson, who isn't the boxer or the puncher Tony is,” said Ali Salaam, Harrison’s father, trainer and a former pro boxer. “With Tony’s punching power, if he hits Charlo with some of the shots Jackson hit him with, I think we stop Jermell.”

 Jermell Charlo made history against Jackson, joining Jermall as the first siblings to simultaneously hold 154-pound titles, although “The Hit Man” has since vacated for a rise in weight.

“We’re not chasing the knockout, but if the opportunity presents itself, Tony is capable of taking the fighter out,” said Salaam. “So if Tony was given the same opportunities Jackson had against Jermell, the outcome would have been different."

Harrison's won three straight since a February 2017 ninth-round TKO loss to Jarrett Hurd (23-0, 16 KOs) for the IBF’s vacant crown,his victories being a unanimous decision over Paul Valenzuela Jr. (October 2017), a fifth-round TKO over George Sosa (February), and a split-decision in May over former champion Ishe Smith.

“Jarrett Hurd is the more difficult fighter than Jermell Charlo,” said Salaam of Hurd, whose 12th-round knockdown secured a split-decision over Erislandy Lara in April, adding the Cuban southpaw’s WBA crown to his IBF version.

“With Hurd at some point you’re going to have to fight him because his conditioning is phenomenal for however many rounds he has to go. But Jermell is going to give us spots where we can take our time."

“Superbad” fought Smith in hostile territory at the Sam’s Town Hotel & Gambling Hall in Las Vegas, where the 6-foot-1 boxer-puncher scored a third-round knockdown and repeatedly bounced right hands off the Las Vegas-born Smith’s badly swollen left eye.

“Tony’s conditioning was great against Smith, where he stood up [in his corner] between rounds over the last five of the fight,” said Salaam. “Tony was boxing on his toes against Smith and finished the fight strong, so we’re going in the right direction."

Harrison had stopped 10 consecutive opponents before losing by ninth-round TKO to Willie Nelson, after which he won three straight (one KO) before facing Hurd.

“We feel Tony’s hands down the best fighter, skill-wise, in the division. He can box if he needs to box, stay in the bucket if he needs to stand in the bucket, and can punch hard enough to stop Charlo in his tracks,” said Salaam.

“We're focused on Tony’s conditioning, his skill set, and him just being Tony. We’re going to take advantage of whatever Charlo gives us. If Tony can be the same Tony in the 12th round as he is in the first, we won’t have a problem.”