He acted as a 'foil for' the comedian. [=he acted very serious to make the comedian seem funnier]
His reserved manner was a perfect 'foil for/to' her bubbly personality.
That dark blue dress is good 'foil for' her blonde hair.
(..) ...after an ATM robbery was thwarted by Queens' own crime stopper... What? As the Spider-Man attempted to foil their heist... ...a powerful blast was set off, slicing through the bodega across the street. If you spot something like that happening, you turn and you run the other way. (..)2017 Spider-Man: Homecoming