In "Magic Duel?" That's the only time I can think of anything remotely close, but she was having her home destroyed by other people, she was laughed at and mocked everywhere she went, and went from performing shows to doing peasant work just to survive. I think it's a lot deeper than just "Twilight upstaged her."
Twilight inadvertently ruined her life, and Trixie was a confused mare at the time. Of course she wanted revenge - think of it like this:
Trixie's life post-Boast Busters is represented by the Dominoes that are falling, the board attached to the machine that knocks over the dominoes is Twilight, and the machine propelling the board forward is the events of "Boast Busters."
Was the Board responsible for knocking over the dominoes? Only the first one in the line.
Was it responsible for everything after that? Indirectly. Had it not knocked over the first domino, none of the other ones would've fallen in line, but it only was directly responsible for the first one.
Could it have avoided it while attached to the machine, though? Nope. Not a chance.
Same applies with Trixie and Twilight in Boast Busters. Was Twilight responsible for knocking the first domino of Trixie's life down? Yes. (Let me add she couldn't have had the slightest clue about everything that would've happened afterwards, though.) Did she set the rest of her downward spiral in motion with the events of Boast Busters? Yes.
Could it have been avoided? Unless she was going to put a whole town's life at risk, it couldn't have been avoided.
Trixie likely didn't take that into consideration and just saw it as Twilight having knocked down the first domino in her life that led to all the other ones falling down as well - blaming the board when the machine was responsible.
Her life was in turmoil, though - all the dominoes were falling down. Even the most intelligent ponies - and people - can get flustered and make poor judgements, and that's clearly what happened here, and therefore is not a result of a lack of intelligence but it's because of the fact that her life was falling down around her and she was unable to deal with it in a proper manner. Very few people can remain composed when their livelihood falls down around them.
It's not because of a lack of intelligence at all. It's because she's only made out of blood, flesh and bone, like every other pony, and wasn't strong enough to remain rational under the great amount of emotional stress she was in.