- The day after Perro Aguayo Jr.'s death (due to an accident in the ring), the cast of Lucha Underground paid tribute to him prior to one of the shows. To paraphrase Konnan, the wrestlers know the risks when they go out to perform for the fans for so many years. It is also hard not to cry for Sexy Star as she is trying to hold back her tears while ringing the bell during the 10-bell salute. You can watch the tribute to Perro here.
- Konnan's heartbreaking story about how he promised Perro's father that he'd take care of him, "But last night, God had other plans." Even worse if you know that Konnan was present at ringside during Perro's last fatal match and futilely tried to revive him.
- Pentagon Jr. and Fenix breaking character and hugging each other.
- During the tribute Fenix collapses to his knees and starts unashamedly sobbing his eyes out. Seeing the man of a thousand lives so utterly broken is almost too much to bear.
- Also Pentagon Jr. wearing a Perros del Mal shirt, representing the long time stable he and Aguayo were members of.
- Puma forcing Drago to retire partially due to an interference from Hernandez. Mitigated by way of 10-Minute Retirement.
- Sexy Star and Super Fly being forced into a Mask-for-mask fight. Super Fly didn't gain any points for blaming her afterwards though instead of Dario, the guy who forced them to do it.
- The Mack coming within a hair's breadth away from winning the Lucha Underground Championship after a grueling All Night Long match, but ultimately coming up short even though he was quite literally one second away from winning before the clock ran out. Everyone, from the crowd to the announcers to his friends Sexy Star and Son of Havoc, are dejected. The Mack himself, after going through all that turmoil only to lose, just falls to pieces and is held by Sexy Star as he breaks down.
- The legitimate shitty luck that Ivelisse and Angelico keep having with leg injuries. In Angelico's case, he injured himself early on in Season 2, which kept him off of most of Season 3 as well, as the in-ring portions were filmed back to back. In Ivelisse's, she was injured just before Aztec Warfare III, which meant that the title win planned for her was switched to Sexy Star instead.
- Prince Puma's last stand at the end of Ultima Lucha Tres. The original star of the promotion, who had main evented the first episode with Johnny Mundo, the inaugural Lucha Underground Champion, finally gets another shot at the Championship that was once his, now held by his one-time friend now mortal enemy Mundo, with his career on the line if he loses. After going through a hellish match, including the traditional "World Wide Underground run in and brazenly beat the shit out of Johnny's opponent" interference, Puma successfully pins Johnny to become the first ever two-time Lucha Underground champion- only for Dario to come out of his office and reveal that Pentagon Dark had come to him right after winning the Gift of the Gods the previous week to cash it in (normally he'd promote this match in advance, but he didn't feel like doing it this time, presumably because it'd be amusing). Even worse, despite Puma winning the championship, Dario puts both men's careers on the line. An exhausted Puma struggles against the fresh Pentagon and is rapidly put in the armbreaker, breaking his left arm, but he bravely tapes it up and fights on. Despite the ridiculous odds stacked against him, he fights back like a true champion and even looks like he's about to win when he sets Pentagon up for the 630 Senton... only for Puma's master Vampiro to stab him in the back, pulling his former disciple Pentagon out of the way of the 630 and causing Puma to fall prey to Pentagon's Package Piledriver, losing his championship and his career despite his incredible efforts. Worst of all, the Believers totally shit on the story, so ridiculously behind Pentagon that they boo Puma out of the Temple, taunting him with chants of "Nananana, nananana, hey hey hey, goodbye!" traditionally reserved for the banishment of cowardly heels like Chavo (with only a few awkwardly remembering to chant "Thank you Puma!" at the last second), even as Matt Striker futilely does his best to sell the cruel injustice being done. As Puma leaves the Temple for the last time he takes off his jaguar mask and discards it on the floor behind him.
- Made even worse once you remember Konan's words in one of the first episodes: for Puma's people, loosing their mask meant loosing their life. Puma taking off his mask could be seen as him loosing his will to live.
- In "A Match Made in Heaven", Saltador is looking in fear as London carries the two away while Mala Suerte is ultimately sacrificed to Mantanza. Clearly, Saltador wasn't expecting any of this when they met the White Rabbit.
- Post-resurrection/time travel Fenix. Seeing what was once the purest tecnico in the Temple become a drooling, seemingly near-mindless monster, not knowing friend from foe, and only barely having flashes of what he once was is utterly heartbreaking.
- To make it worse? "The Moth and the Butterfly" reveals that Aerostar made a Tragic Mistake in reviving Fenix. Catrina's influence has affected him and there is absolutely no way to save him, despite Melissa's protests. What's worse? He states that this small act will cause the end of everything.
- In a way, Catrina falling to her assumed death, as it also signalled the death of possibly Lucha Underground's longest running alliance and the end to a popular character.
Tear Jerker / Lucha Underground