With the offense close to the goal line, Mahomes dropped to pass but had a running lane so wide he could have scored the touchdown himself. Mahomes instead threw into the end zone, where the pass was intercepted by reserve defensive back Leon McQuay.
"That was on me," Mahomes said. "I easily could have run in it. We were in a live period and I kind of didn't want to hear the defense talking trash to me for running it in because they can't tackle me [during practice]. So I threw the ball. ... You just have to play the game how it's supposed to be played [and] don't try to force something in because they can't tackle you. It's just something I have to learn from, and hopefully in a game I just run it in.
"That's the first thing I said when I came to the sideline: I could have run it. [The coaches] said, 'Then just do it. Don't train bad habits.' ... That was the play that needed to be made on that one."
It was a teaching moment for Mahomes and a mistake he might not make again. But it's not the only mistake he has made in camp. He threw two other interceptions Wednesday and has seven in six camp practices. Six of the picks have come during the three practice sessions in pads, when play is most competitive.
"He had a few hiccups today," offensive coordinator Eric Bieniemy said. "But that's a part of the process. When you're young you need those hiccups because they become valuable lessons. ... Would we like for him to be perfect? Yes. We'd like for him to have the highest quarterback rating ever. ... He just needs to be poised under pressure."
Mahomes -- who only played in one game last season as a rookie -- is also making his share of big plays at practice. On Wednesday he threw over the top to Tyreek Hill for a long touchdown pass.
But dealing with interceptions is something new for the Chiefs, who had the conservative Alex Smith as their quarterback for the last five seasons. Smith threw just five picks last season in 505 pass attempts.
Mahomes made another error Wednesday, once calling the wrong play in the huddle. As a result, his receivers were running routes he wasn't expecting and he threw an interception.
That's another mistake Smith rarely made, if ever.
"Being able to get in and out of the huddle, calling the right plays and then not making a bad play worse is something I've got to keep getting better at," Mahomes said.
"I have to eliminate those mistakes. It's something that can be described as a learning process. Hopefully I make those mistakes now and don't make them in the game."
Despite the six camp interceptions, Bieniemy said he's not seeing Mahomes repeat any of his mistakes. They're all the result, he said, of different factors.
He also said he's convinced Mahomes won't throw another interception when such a big running lane is available.
"He even said, 'I could have run it,'" Bieniemy said. "I said, 'Listen, they all count the same. Six points is six points. If you can run it, go get it.'"