It was Keates' first appearance of the season and he was only in the side because newcomer Michael Dobson was sidelined with a head injury.
The Saddlers have already moved to the top of the table after recording their best start to the season in six years.
Keates, in his second spell at Walsall, certainly livened up the proceedings with his spectacular shooting, which consigned luckless Hartlepool to their second defeat in three games.
Pools certainly made hard work of their task as they missed their third penalty of the season, and they are still seeking their first goal.
When Gordon Strachan's son, Gavin, missed his 20th-minute spot-kick as Clayton Ince made a brilliant diving save to his right, it ended Hartlepool's hopes of salvaging anything from the game.
Only two minutes previously Keates opened his account with a rising drive after he had been put in possession by Hector Sam, after Mark Tinkler had been robbed of the ball.
Keates doubled the advantage after 29 minutes when a cross from Martin Butler was headed back into the path, and he responded by sending a rasping left-footed shot past visiting goalkeeper Dimitrios Konstantopoulos.
Hartlepool had their best attacking spell in the second half, after making three substitutions.
But their problems were highlighted by Jimmy Brown, after Anthony Gerrard missed a throughball to leave the substitute with only Ince to beat.
Brown, however, conspired to screw his shot wide from close range to leave Hartlepool bemoaning their indifferent start to the season.