Neither Gretzky or Ovechkin are great shootout/breakaway scorers.
Gretzky relied on being in the right place at the right time for most of his goals, because he could seemingly see a play unfold 5 seconds before anyone else.
Ovechkin has relied on a lethal shot and lethal one-timer for most of his goals, and therefore isn't the best at scoring goals from in close with creativity and patience.
So I think Hasek would stop them both more times than not.
Lemieux, on the other hand, would have a reasonable chance at beating Hasek.
He had a very good shot, superior stickhandling, exceptional reach, and knew how to execute every move and deke under the Sun.
If I could choose 1 NHL player in hockey history to take a penalty shot or breakaway with the fate of the universe at stake, it would be Mario Lemieux.