Brad Garrett -- Outlasts Gambling Superstars ... At World Series of Poker

Don't EVER play poker with the guys from "Everybody Loves Raymond" -- especially Brad Garrett ... who's CRUSHING it at the World Series of Poker ... outlasting one of the best players in the world.

Garrett has lasted into Day 3 of the biggest tournament in the poker world, held at the Rio Las Vegas -- already beating out more than 5,000 people ... including poker superstar Phil Ivey.

A rep for the W.SO.P. tells TMZ Sports ... Garrett is still alive and currently in 1,163rd place.

Ivey was eliminated on Day 2 ... HOURS before Ray Romano -- who also did pretty damn well for himself.

In fact, Romano and Garrett beat out Jennifer Tilly, James Woods and Aaron Paul.

If Garrett wins the whole shebang, he's looking at a pot that's worth somewhere in the $8 MILLION range!!

Stay tuned ...