Using all of his power, as well as the power he has gained from others, Goku delivers a powerful punch to his enemy.
Goku uses this attack at the very end of his battle against Broly, in order to defeat the Legendary Super Saiyan. After gathering energy from Piccolo, Gohan, Future Trunks, and Vegeta, Goku returns to his full power and delivers a heavy punch to Broly's abdomen, launching the Legendary Super Saiyan into the path of Comet Camori and causing his body to crack and his energy to explode outwards, wounding him to such an extent that he fell into a seven-year coma after crash-landing on Earth.
In the TV Special Bardock - The Father of Goku, the captain of Dodoria's Elite uses a very similar technique on his comrade (unintentionally). While landing multiple heavy blows on Bardock (who is held in a Full-Nelson by the captain's comrade), he prepares a powerful one aimed at Bardock's gut, who counters by flipping in midair, causing the captain to punch straight through his comrade's armor (and into his body) instead and was finished off at once by Bardock's Flip Shoot.
In Dragon Ball GT, Super Saiyan 4 Goku uses a similar attack to seriously injure Eis Shenron a little before destroying him wth his Dragon Fist, because the Shadow Dragon used an extremely cowardly blinding strike against him.