Ponchado literally means "punctured" or "flat" (like a tire). However, in Mexican slang, especially in the context of baseball, it means "struck out."
In this song, the artist uses the baseball metaphor of being "ponchado" (struck out) to describe how others wanted to see him fail or be defeated in life. The lyrics, "Me querían ver ponchado y en una rectita, les metí un home run," vividly illustrate his triumph over those who doubted him, turning their expectations of failure into his success.
Los Dos Carnales' "Home Run" is a fantastic song about overcoming people who doubted you. The singer talks about how when he had nothing, people treated him badly, like their "perro" [dog]. They wanted him to stay down, thinking he'd always be "batallando por lo mismo" [struggling with the same things].
But now things are different! He's found success, thanks to God, and he's not shy about telling those who "me humillaron y me hicieron menos" [humiliated me and made me feel small] to "miren dónde estoy" [look where I am]. He uses a great baseball metaphor, saying they wanted to see him "ponchado" [struck out], but instead, "en una rectita, les metí un home run" [on a straight pitch, I hit a home run]! He's got "casa llena" [bases loaded] now, and he's just leaving his haters "viendo" [watching] as he moves forward. It's all about hard work paying off and proving people wrong.