Jack Marshman says he disobeyed the Army to fight at UFC London where he beat fellow Welshman John Phillips on Saturday at the O2 Arena.
The full-time Paratrooper, who says he will retire from the military in November to focus on UFC, said his employers had to told him not to fight.
"They sort of told me that I wasn't fighting this weekend on Thursday, so I was packing my bags and running away like," the 29-year-old said.
Marshman won by split decision.
"How did I work it out with the Army? We will find out on Monday won't we?" he said. "Legally I am contracted to the Army."
'I will work it out with the Army'
The first fight on the main card of UFC London was dubbed the 'Battle of Wales', but there was more than national pride at stake with the loser of the middleweight bout knowing their place in the UFC may also be under threat.
Abertillery's Marshman won the contest by split decision 28-29, 29-28, 29-28 on the cards.
However, having weighed in two pounds overweight and forfeiting 20% of his purse, Marshman revealed he and the Army were in conflict over whether he should fight.
"I'll work it out with the Army," he said. "They will see what they want to do, you can't be employed by two people at the same time, if you understand me."
BBC Sport has contacted the Army for a response.
'UFC is just my hobby'
Marshman says he had already planned to leave his full-time job in 2019 to focus on his UFC career after picking up a vital win.
"I am a full-time Paratrooper; this is my hobby," he said. "I am fighting at the highest level possible in MMA but I am doing it as a full-time Paratrooper, that is my profession, that is my job.
"I am leaving the Army in November and will be able to do this full-time.
"I wanted to do that anyway, I will have done 12-years then, I want to get my half pension.
"Full-time training will make a big difference, I haven't reached my 30s yet. I am learning every day."
Winning the 'Battle of Wales'
Marshman says he was not hurt in the bizarre incident in which Phillips bowed to Marshman and allowed him to get up after knocking him to the floor with a right hook during their fight. Phillips stopped to let his countryman to his feet before sharing a high-five.
"He caught me off balance with the knock down," he said. "I wasn't hurt by it, that's why we were laughing.
"The win means a lot... If I had lost, that is a 12-year army career I would have given up for nothing."