Dan Evans said Kevin Pietersen sent him into "some serious rage" after the former England batsman "handed off" the Australian Open surprise package when he asked for a picture in Melbourne.
Evans beat Bernard Tomic in straight sets on Friday to reach the last 16 of a grand slam for the first time, but the Englishman had a moment to forget in a casino earlier in the week.
The world number 51 was snubbed by Pietersen, who is plying his trade for Melbourne Stars in the Big Bash League, when he asked for a photograph.
Pietersen apologised after Evans tweeted him about their brief meeting, replying: "Apologies mate! I started drinking at 1pm so didn't even know my name by the time that function started!"
@Evo151216 apologies mate! I started drinking at 1pm so didn't even know my name by the time that function started!-- KP (@KP24) January 19, 2017
Straight-talking Birmingham-born outsider Evans said after his shock win over Tomic: "He didn't want me to have my picture with him. That was it. I think he was worse for wear.
"That was his excuse when he replied. Quite funny, isn't it, how things work out? He was my favourite cricketer until that point, genuinely was.
"But there was some serious rage for about 20 minutes after that happened. There was some serious rage. Yeah, it was a bad moment that was. It was so embarrassing, as well.
"He didn't even just say no, he handed me off, as well. I was nowhere near him either. Oh, God, yeah, it was really embarrassing."
Asked if Pietersen was busy gambling at the time, Evans said: "No. I would understand if he was playing a game or something. I wasn't in the casino. I was coming out of the restaurant.
"He was walking down the hall. I mean, he wasn't even getting hassled or anything. He was just with three friends. There was no one around him. I'd get it if everyone was asking him.
"It was amazing. I heard that's not such a surprise to some people."