Webster's 4-53 from 20 quality overs stamped the Test allrounder's class when the game was on the line as the Bulls collapsed to be all out for 221 in a run chase that never looked likely.
Queensland entered the match at Bellerive Oval with a chance to finish second and reach the Sheffield Shield final with an outright win but their batters let them down, as they have done in recent matches.
In their final 10 innings of the Shield season, which included one incomplete innings where they were 6-44 before being saved by rain, Queensland passed 200 only twice.
It was a case of more of the same against Tasmania, when the Bulls' batters managed a first innings of 178 after the bowlers had toiled well to restrict the hosts to 198.
Bulls captain Marnus Labuschagne and opener Matt Renshaw needed hefty scores on the final day to give Queensland any chance of making the 362 runs set for victory, but both fell for 29.
The duo had been in wonderful Shield form earlier in the season, with Labuschagne notching two centuries and Renshaw three.
But since returning from international duties both have found runs elusive.
Renshaw edged a seaming Webster delivery to Jordan Silk at first slip while Labuschagne was the victim of brilliant fielding.
Jack Clayton punched to point and called for a single but Kieran Elliott swooped and hit the stumps from side-on with Labuschagne well short.
Webster had Lachlan Hearne (eight) nicking off and the Bulls had slumped to 4-73.
Allrounders Michael Neser (23) and Xavier Bartlett (36) played entertaining cameos after Webster had dismissed Clayton (30), the last of the recognised batters, who chopped on.
Billy Stanlake and Elliott both picked up two wickets in a strong Tasmania team display to end their sea
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