Marcos Ambrose provided his side Thursday of the postrace fracas at Richmond International Raceway, repeatedly citing "passion" as what provoked his punch of Casey Mears.
Ambrose was fined $25,000 and placed on probation for his role after Saturday's race. Mears was fined $15,000 and also given probation for the incident, which began with him grabbing Ambrose in the RIR garage.
"I was confused about why Casey was so annoyed at me, and I think you just see a lot of the passion that the drivers have and the commitment we have to try to win," Ambrose told reporters during at promotional event at Charlotte Motor Speedway. "That passion kind of got out of hand and got out of control pretty quick. Once he put his hand on me and started pushing me around, I was just trying to stand up for myself and my country and my family and my reputation, and I threw a punch down on him to get him out of the way and let him know that I didn't respect him not giving me my private space."
Ambrose said it was an "impromptu" altercation. The native of Tasmania was intercepted by Mears while heading to tell driver David Gilliland "we're all good" after they made contact a few times in the race.
"A wiser man would have walked away a little bit earlier and not got himself in that situation," Ambrose said. "I don't apologize for my actions. I was just standing up for myself and my team and my family and letting people know that you can't get in my private space like that and expect not to have any consequences."
Ambrose and Mears, who finished 18th and 19th at Richmond, talked Monday, and both said they've put the incident behind them.
"We've spoken in-depth more than once," Ambrose said. "I honestly believe that we'll enjoy having a beer with each other. I think we have a mutual respect for each other. I like Casey a lot. I didn't have any beef with him after the race, but emotions just got out of hand and we both recognized that if we had our time again it wouldn't happen again, but now it has, you can't take back what has happened.
"I'm not carrying anything forward. He has to decide what he wants to do moving forward, but if we get ourselves in a pub somewhere I'd buy him a beer no problem."
GOOD CONVERSATION: Mears says he and Ambrose cleared the air
Ambrose, who raced V8 Supercars in Australia before coming to NASCAR in 2006, said he happily would pay the largest fine of his career because "I got myself in a bad situation. I caused an action that NASCAR needed to reprimand."
Video replays of the incident suggested Ambrose was confronted by a crew member after striking Mears, but Ambrose said he wasn't punched.
WATCH: Ambrose and Mears come to blows at Richmond
"I was able to duck and weave and get out of trouble," he said. "I've had a phone call from somebody to apologize for his actions and that's it for me. I've got no beef with him, either. I'm happy to move on and put the week behind us."
Ambrose, 37, is in his sixth season of competing in NASCAR's premier series and has won twice in Cup with the No. 9 Ford of Richard Petty Motorsports. Both wins were at Watkins Glen International in 2011-12, and the latter was a memorable last-lap duel with Brad Keselowski.
"I think my NASCAR career may well be remembered by one of the best finishes of all-time and one of the best fights of all-time, too," he said. "It's OK. Our sport is made up of passion and everyone has their own angle. Certainly, it's not a great thing to explain to your kids on Sunday what you did. I'll take that penalty and the repercussions from my actions and pay it, and then people can do whatever they want from there."
Ambrose said he and Mears talked for 90 seconds before it turned physical.
"He was mad at the race, and he was mad at himself, and we were around each other at the end of the race," Ambrose said. "It's a full-contact sport. I was actually pretty calm (after the race). I think one of the reasons I laid down such a good shot on him was that I wasn't riled up.
"I was actually fairly lucid in my thoughts and was able to get a good punch off because I wasn't bound up with too much adrenaline, but adrenaline is just part of what we do."
Ambrose said he hadn't been in a scuffle before and "that just shows you the passion we have that I'm able to get myself in a physical fight and draw a claret to finish 18th. That just shows you how deep the talent is and how much passion and commitment we all have to what we're doing."
Team owner Richard Petty, who also attended the event with Ambrose, said his driver had a right to self-defense.
"You've got to defend yourself no matter what, but if he knew he was going to be fined $25,000, he might have let the guy take another swing at him," Petty said with a laugh. "As you can see in the tape, he did not initiate any of that.
"I always look at it as you have to defend yourself no matter what the circumstances are, and that's what I saw in the Marcos situation. What provoked it? I have no idea. I don't even think Marcos knows really what provoked the whole thing. But in the scheme of things if you can't protect yourself, then NASCAR is not going to come and protect you, so he had to do what he had to do."