Scott Fenwick had flicked Pools ahead on the half hour but the visitors lead lasted only five minutes as Ryan Bird netted his fourth of the campaign. But Walker's goal, coming just two minutes after his introduction, saw the Glovers fail to continue their recent upturn and drop back into 21st place in the League Two table.
Yeovil boss Paul Sturrock sprang a surprise on his team sheet with the news that Josh Sheehan had re-signed for the club on a three month loan deal. The Swansea youngster went straight into the starting eleven with 17-year-old Ollie Bassett retaining his spot up front alongside Ryan Bird. Sheehan replaced Josh Wakefield, another loanee, who has returned to parent club AFC Bournemouth.
The first half hour was devoid of real clear cut chances as play was mainly in the midfield, punctuated by several misplaced long balls and although Yeovil tried playing through the thirds, there wasn't much for either striker to feed on. The nearest either side came to scoring was a Sheehan effort that whistled a foot or two over the crossbar from Connor Roberts' cross.
On 31 minutes, the opener came and it had an element of farce about it. Pools left back Jake Carroll swung in a free kick that seemed to go through everyone and end up bouncing into the net at the far post. Scott Fenwick wheeled away in celebration, later acknowledging he had the final touch.
The lead was all too brief for Ronnie Moore's men though as the Glovers responded almost immediately. Nathan Smith was the architect with a brilliant piece of control that saw him escape his marker and find Jake Howells just inside the box. His cross was converted at the far post by Ryan Bird.
Sheehan then went close to putting Yeovil 2-1 up before half time with a rights foot shot that almost flew into the top corner and Billy Paynter had Yeovil keeper Artur Krysiak scrambling right on the break with a left foot effort that rolled wide.
The second half begun in controversy with Jakub Sokolik going off for treatment for a nose bleed but although ready, being refused permission to come on to the pitch for more than a minute. It took until the ball next went out of play for the official, Fred Graham, to allow the defender to resume playing.
Pools defender Scott Harrison looped a header over the bar but Yeovil were more threatening after the interval with Howells and a Matt Dolan free kick going close to giving Yeovil the lead. And they came even closer on 68 minutes when a superb flick on from Ollie Bassett found Howells but his right foot rasping shot found the side netting,
The winner came on 82 minutes and as with Hartlepool's equaliser, there was an element of fortune in it. The ball was played from one side of the field to the other where it found Pools sub Kudus Oyenuga; his shot seemed mishit but found sub Brad Walker and he thumped the ball home gleefully to grab all three points.