OLL 26
Exactly one top corner is yellow. Sune and Antisune are mirror images: compare where the other three corners point in the diagram.
R U2 R' U' R U' R'7 moves · Probability 1/54 · 2-look OLL step 2 (corners) · Mirror: OLL 27

Setup: apply these moves to a solved cube to reach this case
R U R' U R U2 R'Other algorithms
Dashed keys are AUF: a U turn that lines the top layer up with this algorithm.
UL'U'LU'L'U2LU'R'U'RU'R'U2R