Kieran Culkin Spends Most of SAG Awards Speech Fixated on Trophy's Weight

Kieran Culkin gave the first thank you speech of the SAG Awards ... or, at least he meant to -- but, he just couldn't get over how heavy the trophy was.

The actor accepted the trophy for Male Actor in Supporting Role in a Motion Picture ... and, while it seems he may have meant to give an actual speech, when he grabbed the trophy that went out the window.

Check out the clip ... Culkin receives the trophy and begins talking about it's weight -- and, he just can't stop.

He puts the award down on the table next to him -- commenting about how that must be what it is for before launching into a bit about how actors must have designed the heaviest award for themselves to prove their profession's importance.

The bit goes on and on ... before Culkin finally says he needs to actually say something and thank some people -- including his pal and "A Real Pain" director Jesse Eisenberg.

He rattles off a series of names in about 30 seconds before walking off ... unclear if he got everyone -- but, it's a nice recovery after clearly being distracted up to that point.

BTW, "Shogun" star Anna Sawai agreed with Culkin -- admitting it is heavy at the end of her own speech for winning the Female Actor in Supporting Role in a Drama Series award.

It's just the latest award Culkin's won for his part in the drama movie about generational trauma set in Poland. He's already won a BAFTA, Golden Globe and Critics Choice Award for the part, and he's up for an Oscar next week too.