Ben Knight's early second half goal for the Yellamen was cancelled out by Slimbridge's Liam Harding but a neat ball through to Taylor Mitcheson in added time was held up well and his pass across was eventually met by Waddieh who slotted the ball home for what turned out to be the winner.
The Yellamen now have 12 points from 10 games but have at least four games in hand over the rest of the field.
Meanwhile Binfield are five points off the top of the league with a 2-1 win over Cheltenham Saracens.
Seb Bowerman's pace and calm finish opened the Binfield account just after the half hour and a minute later, Garry Sargeant followed last week's hat-trick with a peach of a finish with the outside of his right foot to curl in the Moles' second.
Saracens hit back just before the hour through Elliott Kennedy and later hit the post but the Moles held firm to secure their second successive victory.
Wokingham & Emmbrook were held to a 1-1 draw by Highmoor Ibis and remain unbeaten in the league since the end of August.
Anthony Alleyne scored for Highmoor with Dan Bateman scoring for the Satsumas.
Bracknell Town beat Milton Utd 3-1 in Division One East with goals from Reece Jacques, Eddie Gray and Lee Riddell. Joe Parker replied for Milton.
In the same division, Finchampstead lost 4-1 at home to Didcot Town Reserves.
Sandhurst Town's miserable season in the Combined Counties Premier Division continued with a heavy 6-2 defeat at Windsor.
The Fizzers were 4-0 down at half time but pulled back two consolation goals late on through Josh Watkins.
Free-scoring Matt Baker scored five times for Eversley & California as they continued their scintillating form to beat Farleigh Rovers 6-0 in Division One.
Chris Fox also weighed in with a goal to make it 41 goals scored in just 11 games.