In Part 17 of her Donkey Kong Country Returns LP, Masae tries to beat a Kong level for about 9 minutes and rage quits after failing right at the end. When she comes back, she screws the commentary and remains completely silent as she beasts her way through the level while only getting hit once. Manly Masae, indeed.
Her getting the One-Hit Kill effect of Geno Whirl on her first use of the move in Super Mario RPG. The fact that it's a blind run makes it even more impressive.
She later uses it on Yaridovich's mirage, one of the very few bosses it works on, and even deduces that it might work herself. Again, pretty impressive for a blind run.
Also, she actually manages to stumble upon the "Fertilizer" on her own, and uses it to get the Lazy Shell weapon and armor, two of the best items in the game. In a blind run.
And after a tense battle, she won against Smithy in her first attempt without using Peach or the Lazy Shell armor and using Mallow and Geno. This includes a close call when Smithy in his second form decided to use the Scarecrow attack in his Box head, which turned everyone (sans Mallow) into one, leaving her without the chance of using items after realizing she couldn't use those as a scarecrow just after Mallow got hit by Magnum and OHKO'd him before she could get a turn to use a Freshen Up.