Demetrious Johnson was KO'd with a knee as wild violence marked One Championship's breakout US cable show

• Adriano Moraes knocked Demetrious Johnson out with a knee to the face.
• It went down at One Championship's big card on TNT - US cable TV.
• Eddie Alvarez was disqualified earlier in the event, and Rodtang scored another win.

Wild violence marked One Championship's coming out party on US cable Wednesday as Muay Thai expert Rodtang walked through punches to score a win, Eddie Alvarez was disqualified, and Demetrious Johnson was KO'd with a knee.

Chatri Sityodtong, the One CEO, told Insider earlier this week that April was set to be the biggest month in his company's history as he looks to increase visibility for his Singapore-based promotion in the US.

Had the Kallang event taken place in the US, the results would have been different, but given its location, a different set of rules, which permitted strikes to the head of a downed opponent, applied.

This benefited One's flyweight champion Adriano Moraes who cracked Johnson's skull with his kneecap while the American was in a downed position in the second round of a vicious 135-pound headlining fight.

Johnson was one of the most dominant athletes in all sports throughout the 2010s because of a lengthy rule over the UFC's flyweight division.

He moved to One two years ago, beat three of Sityodtong's 135-pounders, and won the company's flyweight Grand Prix to set up a high-stakes fight with Moraes.

The tough Brazilian grappler asserted his authority over Johnson in the opening round of their fight, dropped him with strikes in the second, before throwing the knee.

The legal strike - a short but crisp left knee that Moraes lifted from close-range - sent Johnson crashing backward, prompting the referee to intervene quickly.

It was all over.

Moraes had beaten a legend in a decisive fashion, and became the first person to finish Johnson.

Watch it right here:

Earlier in the night, Eddie Alvarez's campaign for a One Championship title shot took a strange turn when the star American fighter was issued a red card for strikes to the back of the head.

Alvarez had been performing well against Iuri Lapicus, scoring a takedown early in the first round, before wailing strikes on his 170-pound lightweight opponent.

The referee adjudged shots at the end of a sequence to have been illegal and called an end to the bout.

Lapicus won via disqualification and Alvarez was sent home with a second loss in three One Championship appearances to date.

Watch the controversy here:

Lapicus was taken to hospital after the fight but Sityodtong said he's in "stable condition," according to MMA Fighting reporter Damon Martin.

It is currently unclear where Alvarez will go next. Sityodtong had previously told Insider that Alvarez was two wins away from challenging for the One Championship title, which currently belongs to Christian Lee.

The company's president told us Alvarez would need to beat Saygid Guseyn Arslanaliev, nicknamed "Dagi," before he could get to Lee. That could be a bout that materializes should a rematch with Lapicus fail to transpire.

Elsewhere on the One card, Rodtang added another win to his record as the Thai boxer outpointed Daniel Williams.

Watch Rodtang floor Williams with a left hook here:

One Championship returns to TNT, cable TV in the US, on Wednesday, April 14 for another event.

Christian Lee defends his title against Timofey Nastyukhin in the main event of a six-bout card at the Singapore Indoor Stadium.