Fresh off his impressive 6th round knockout victory ... boxing champ Andre Berto splurged on some blueberry lemon waffles at an L.A. breakfast joint -- and left one hell of an impression on his server.
TMZ Sports has learned ... Berto and his buddy hit up The Waffle in Hollywood early Monday morning and racked up a $46 bill on some breakfast goodness.
And the food musta been bomb ... 'cause AB was in such a good mood after his meal, he left a $200 TIP ... along with the note, "Pay it forward #TeamBerto."
"My server was real cool," Berto said ... "I felt like I needed to give him a good tip, so I did."
"I was gonna leave $500 but I didn't wanna go too crazy."
We also spoke with the waiter who says Berto is officially his favorite customer ever.