"He made plays, and he did it with his legs, he did it with throwing, he did it with checks,'' Reid said of Mahomes' 256-yard, four-touchdown performance. "I have a lot of respect for [Chargers defensive coordinator] Gus Bradley and his defense. He threw a few things at Mahomes. He got him a few times. But I thought Pat did a nice job of handling it against an experienced and very good defensive coordinator.
"He's a unique kid. He's got to keep working here. He's just at the beginning of this thing. We've got to keep moving forward, taking steps forward.''
From the outset, Mahomes looked like he was having fun. He threw his first touchdown pass, for 58 yards to Tyreek Hill, on his third pass of the game.
"He was very comfortable,'' Hill said. "Every time he stepped into the huddle, he was very confident in the playcalling. He was like, 'OK, guys, let's drive this ball down their throat.' As receivers, tight ends, offensive line, we're like, 'OK, we've got a great leader in our huddle.'''
That was a change from Mahomes' only previous start for the Chiefs, in the final regular-season game last year against the Denver Broncos. He was so pumped up then that early in the contest he threw a pass several yards past an open receiver for an interception.
He made no such errors against the Chargers. He played a mistake-free game, one reason the Chiefs were able to maintain their lead the rest of the way after scoring a touchdown just two minutes in.
Mahomes even made some veteran decisions. He kept the ball rather than hand off to Kareem Hunt on the long touchdown pass to Hill. The play was a run-pass option and Mahomes noticed a linebacker heading for Hunt and vacating the middle of the field, where Hill was headed.
Unlike his coach, Mahomes did find a fault in his game.
"There is stuff that we have to keep working on and I have to keep learning from,'' Mahomes said. "I'll see that from the film, but just from being out there, there was stuff that I could have hit that I didn't. On one instance, I was protected but I thought it was going to be [pressure from the Chargers]. Sammy [Watkins] was wide open and I could have made the throw.
"There's just little stuff like that that you have to keep improving in order to have success in this league.''