Trailing by 2-0 at half time, three further goals in the space of six minutes shortly after the break gave the hosts an unassailable lead and ensured they could play out the remaining 40 minutes with relative comfort.
Slough started fairly well, with Warren Harris, making his first competitive start since returning from his ACL injury, a particular threat with his direct running at the Waders defence when he was fed the ball.
But with 12 minutes gone, a mistake in the left-back position from Ryan Parsons allowed Ian Rees to wriggle through and get in a low cross to the unmarked Burnett, who tapped in to an open goal.
Six minutes later, the hosts doubled their lead. This time, a free kick conceded needlessly by Callum Webb was swung in by Shaun Hill, and the impressive centre-back Gavin Hoyte flicked a header past Mark Scott and into the far corner.
Slough were in serious danger of collapsing at this point, with Eddie Smith perhaps lucky to avoid a more serious punishment than the yellow card he received for a rash tackle on Craig Daniel, and two minutes later, with just 21 minutes on the clock, Jay Davis was unlucky to see his low angled drive rebound back off the inside of the post and into Scott’s arms.
Biggleswade keeper Ian Brown saved well from Nathan Webb’s long range strike as Slough looked to reverse the pressure, but his opposite number Scott was busy again to keep out an effort from Davis at the back post on 30 minutes.
Scott thwarted the Waders again later in the half as he helped Daniel’s long-range effort over the bar, whilst Jamie McClurg tried a shot from distance, but saw it deflected over.
Half-time arrived with Slough fortunate to only have a two goal deficit, but things were to go from bad to worse very quickly for the hapless Rebels.
Two minutes into the second period, Biggleswade worked the ball to Daniel on the right side, and he advanced into the penalty area and drilled a shot through the legs of Scott at his near post to make it 3-0.
Within two minutes, a slip from Scott allowed Burnett to claim his second and the Waders’ fourth.
Another three minutes later and Biggleswade had unbelievably claimed a fifth goal. A precise through ball split Adam Martin and Guy Hollis, and Burnett raced clear and clipped the ball over the advancing Scott, who raced back towards his goal-line with Ryan Parsons, with neither able to keep the ball out of the net – a catalogue of errors for Slough, but reward for a rampant Waders side.
With the game gone, Slough withdrew Warren Harris and also Smith, who limped off with a tight hamstring.
On 70 minutes, Nathan Webb weaved his way into the box and tried to curl a shot into the bottom corner, but his attempt was deflected wide.
Slough kept the pressure on in the search for a consolation goal, and McClurg’s well-struck shot from 25 yards was well held by Brown, whilst Nathan Webb sent another long-ranger wide.
Four minutes from the end, Callum Webb swung an inch-perfect free kick into the six yard box, which Scott Harris slid in to meet, but put wide.
Slough at least deserved a first goal of the season for their efforts in the second half, and were rewarded as Callum Webb got in a good strike from the edge of the box which beat the dive of Brown, a debut goal for the full-back.
Biggleswade Town Line up
Ian Brown, Charlie Hunter, Mark Coulson, Shane Hill, Gavin Hoyte, Andrew Iwediuno, Craig Daniel (c), Callum Lewis, Tony Burnett, Ian Rees, Jay Davis. Subs: Kyle McNulty, David Hutton, Sam Merson, Michael King, Ryan Blackman, Macsen Fraser.