Crawley celebrated their first game for a month with a 2-1 win at the Banks's Stadium which severely damaged Walsall's play-off hopes.
A goal in each half from Matt Tubbs - the first a fourth-minute penalty - was enough for all three points despite Sam Mantom pulling one back for the Saddlers.
And the visitors held on after striker Billy Clarke was sent off for a second yellow card when he was booked for time-wasting 10 minutes from the end of the game.
Tubbs opened the scoring from the spot after home skipper Andy Butler accidentally handled the ball in the box in his first game back after a one-match suspension.
He headed a second for the Red Devils in a 51st-minute breakaway when Clarke found him with a great far-post cross.
Walsall were back in the hunt after 64 minutes when Mantom met a Craig Westcarr corner, and they piled on the pressure in the closing stages but Crawley defended brilliantly to hang onto the points and inflict a second successive home defeat on the Saddlers, who are now five points behind sixth-placed Peterborough.