S2·E25 Yamato: Invasion of the Imperial City

Just as Earth officials are leaving to sign the surrender agreement, the Star Force begins its surprise undersea torpedo attack. They roust the fortress aloft.

After a frantic fighter battle above Earth, in which we later learn that pilot Hardy has died, a desparate invasion task force -- Wildstar, Sandor, Conroy, Knox, et al. -- penetrates the Comet Empire through openings in the bottom side. Sandor's bionic leg is blown off the ensuing shoot-out. Sgt. Knox manages to reach the Comet Empire energy centre. He tells Wildstar and Sandor to return to the Argo, and that he will follow. Once they are outside the Comet Empire, Knox manually sets off the small hydrogen bombs that destroy the energy center (and actually Knox too, though English dialogue denies this).

The Star Force launches one, final, all-out barrage against the powerless Gatlantis fortress. The rubble churns into fire.

When victory is thought won, a deadly black ship, Zordar's dreadnaught, rises from the ruins. Zordar threatens to leave Invidia and General Dire behind in the exploding fortress for all their meddling (actually, in the Japanese version, he does!).