Tatsumaki could (probably) crush Boros like a bug. Boros's power comes from his internal "latent energy". We know this can be suppressed, because he wears armor that was built to do exactly this. Fubuki has demonstrated that she can use her power to restrain and suppress energy like this when she stopped Genos's core from going critical and exploding. If Fubuki can use her power to do this then it's probably fair to assume that Tatsumaki can do it better.

If Tatsumaki thinks to suppress Boros' latent energy, she could probably just snuff him out like a candle.

That said if Boros was somehow able to ambush Tatsumaki when her defenses are down he could probably one shot.