Both men exchanged heated words at the weigh-ins, and Klose taunted the Brit and his fellow countrymen after his upset win at the T-Mobile Arena in Las Vegas, calling all English fighters 'bums'.
Current UFC middleweight champion Michael Bisping, who is the only British champ in the promotion's history, was ringside for the event and did not look happy.
Klose, who beat Diakiese via split decision, apologized at the TUF 25 Finale post-fight press conference and said he got caught up in the 'heat of the moment'.
“It was just the heat of the moment,” Klose told the media after the bout, per Ken Hathaway of MMA Junkie. “If you look at my Twitter, me and him have been going back and forth since the fight was announced. After the fight it just got under my skin, and it came to a head, and I just let it go. My roommate right now is Bradley Scott, and he’s an English guy, and he’s fighting August 5. It was just the heat of the moment. I apologize to everyone for saying that.”
Klose, who was antagonized by Diakiese in the weeks leading up to the bout, believed he handled 'Bonecrusher's' trash talk well, all things considered.
“I think (talking is) what he does to get in (his) opponent’s head,” Klose said. “He intimidates them like that. I’m a different breed. I train with Benson Henderson every day. I get beat up by him. This guy, he’s not going to go in there and do that to me.”
Despite winning via split decision, Klose believes he won every round and thought he dominated the fight.
“In my head I thought I won every round,” Klose said. “I don’t think it should have been a split decision. Marc, he has all this hype behind him. I knew that he wasn’t going to be as tough as everyone thought.”
Klose, 29, is currently unranked in the UFC's lightweight division but is willing to fight 'anyone', including No. 1 ranked contender Khabib Nurmagomedov.
“I just want to fight in Detroit,” Klose said of his next bout. “They can put me against anyone. I’ll fight Khabib (Nurmagomedov), I’ll fight anyone. I don’t care. Just put me in there. I’ll get my hand raised.”
The Ultimate Fighter 25 Finale, which saw Klose beat Diakiese on the main card, ended on a high note with Justin Gaethje vs. Michael Johnson. Gaethje and Johnson electrified the T-Mobile Arena with their back-and-forth brawl, with Gaethje eventually finishing 'The Menace' with a crushing knee in the second round.