Angels fans let the cheating-ass Astros HAVE IT during their game in L.A. on Monday night ... chanting insults at them and trolling them with a symphony of banging trash cans!!!

The scene was epic ... in right field at Angel Stadium of Anaheim, fans had a seemingly endless supply of garbage bins to heckle Houston players with.

It started early in the night when one fan lifted one over his head and banged on it incessantly.

Later, one person actually threw an inflatable trash can onto the field. Then, just minutes after that, someone dumped an entire bin over the wall!

Things got so relentless -- the Angels actually had to set up security in right field to make sure it all calmed down!!!

Eventually, the trash bins seemed to get to Houston ... 'cause it blew a 5-3 lead late in the game and ultimately lost, 7-6!

And, the limited capacity crowd sure let the Astros know about it ... joining in unison to chant "Astros suck!" at players.

Of course, the 'Stros are still hated by everyone after MLB officials determined they illegally stole signs and banged on trash cans to relay them to batters during their World Series run in 2017 and the following year.

The players caught a bit of a break last season with no fans allowed in stadiums ... but it's clear, they ain't gonna get the same kind of treatment this year.