User blog comment:Kuopiofi/Saitama - Absolute or Supernatural?/@comment-25893909-20160906164927/@comment-24053170-20160908172619

Saitamas greatest strength is also his biggest weakness as well unlike the other heroes in the series saitama has to make contact with his opponent to win the fight. So the easiest way to take saitama out of action (not merely defeat him, but rather leave him in a position were he can't do anything) is simply leave him drifting in space. just like anyone else in the series except for those that have adapted to space, saitama has no method of controlling his movement without a solid surface to stand on.

In fact if boros' attack hadn't set him to the moon, but instead left him drifting around in the vastness of space. there wouldn't be anything he could do anymore.