Blake earned Burnley only their second win in nine games when he converted a 56th minute penalty.
It sealed a win that Burnley thoroughly deserved as they dominated almost the entire 90 minutes.
They would have secured a more comfortable win but for some poor finishing.
Walsall reserved one of their worst displays of the season for the day when a win would have put them within touching distance of safety.
But they are again in the thick of the relegation battle and face a crucial trip to fellow strugglers Gillingham on Monday after losing only their second game in seven matches.
Burnley should have been out of sight by half-time as they dominated the opening period only to waste a hatful of chances.
But, ironically, Walsall, who struggled to get out of their own half in the first 45 minutes, did have the first real chance to break the deadlock.
It needed a fine save by Burnley goalkeeper Brian Jensen to deny the Walsall skipper Paul Merson in the 21st minute.
But that was the only time that Jensen was tested as Burnley laid siege to the Walsall goal.
Leading scorer Robbie Blake squandered two clear openings - being denied by goalkeeper James Walker after 23 minutes and then shooting wide three minutes later.
Glen Little headed over the bar and Tony Grant was frustrated by Walker before Neil Wood threw away Burnley's best chance of the half.
The on-loan Manchester United midfielder was unmarked just 12 yards from goal after being set-up by Blake, but Wood failed to get his shot on target and sliced his effort wide.
Despite his miss it appeared only a matter of time before Burnley's pressure paid off and that proved to be the case 11 minutes into the second half.
A rash challenge from the Walsall midfielder Craig Burley on Wood left referee Steve Bennett with little option but to point to the penalty spot.
Leading scorer Blake calmly sent Walker the wrong way from the spot.
Burnley should then have set the seal on their win only for Paul Weller and Ian Moore to throw away another two golden chances.
Blake was also frustrated five minutes from time by Walker.