Quill Attacks Thanos

The Guardians, Doctor Strange, Iron Man, and Spider-Man have successfully subdued Thanos on Titan. Mantis has sedated him while Nebula is unoccupied. Star Lord interrogates Thanos, demanding to know where Gamora is. Thanos, who had just sacrificed Gamora to get to the Soul Stone, starts mourning, which Mantis picks up on as she's restraining him. Nebula then explains that Thanos killed Gamora for the Soul Stone, to which then Thanos in his sedated state confirms. Rather than waiting for the others to finish retrieving the Infinity Gauntlet, Quill, in a fit of rage starts attacking Thanos causing Mantis to lose control of him. Thanos then manages to retrieve the gauntlet from Peter Parker, making the entire group effort for nought.

Example of:
Nice Job Breaking It, Hero