The Thornes forged ahead a minute before the break when a clearance from home keeper Daniel Lee was flicked on by Daniel Lassman into the path of Dave Ossack. He got the slightest of touches to lob the ball over Brady stopper Oliver Colmans.
Buoyed by the goal, Walker almost added a second just after the interval but his effort was well saved after he had twisted and turned past two Brady defenders.
Jamie Golding and Ossack both had good opportunities to make the game safe but lacked the finishing touch.
At the other end, Kane Gilbery shot wide from 15 yards which was the nearest Brady came to a goal. Glenthorne made absolutely sure the title of a return to the top-flight at the first time of asking when James Rubin supplied a superb cross for Walker who headed home at the far post.
Glenthorne manager Ian Cohen commented: “My team were determined and disciplined but credit to Brady who I am told were without a couple of key players. They certainly came to make a go of it so we were delighted to get the three points, and with it came the culmination of a great season, winning the title in style.
“It has been a great campaign and to receive the trophy from league chairman David Wolff is a great reward for the team, who to a man this season have been fantastic. The entire squad has played a part this year and I am very proud and honoured to have been in charge of such a great group of lads.
“For now we are just celebrating the achievement but I am already starting to plan for next season and will now be looking to add one or two top quality players. We must remember that our average age, apart from Robert Donn and Neil Zeff, is still only 21 years and we look forward with relish to the challenge ahead.”
Brady boss, Lynton Stock who had come on as a substitute in the last 15 minutes to make a rare appearance for the club, reflected: “I thought we played very well and I am very proud of my team. We had a several players missing but they gave a good account of themselves. All credit to Glenthorne who are worthy champions.”
Glenthorne: Daniel Lee 7, Craig Mervish 7, Neil Zeff 7, Jerome Marks 7, Robert Donn 6 (sub: Daniel Cooper 6), Jamie Golding 6, Daniel Lassman 7, (sub: Paul Block 6), Dave Ossack 8 (sub: Alex Lishak 6), Lewis Walker 8, James Rubin 8, Jamie Cooper 7
Brady: Oliver Colman 7, Joel Lassman 6, Matt Gilbery 7, Robert Kleinman 6, Ryan Moscow 7, Kane Gilbery 7, Andrew Shuster 6, Oliver Kenner 6, Daniel Stock 7, Johnny Winton 7, Richard Winton 6 (sub: Johnny Meltzer 5), (sub: Lynton Stock 7)
Glenthorne were crowned Division One champions at the first time of asking