Welling took the lead in just the fourth minute through Alexander, after Temi Eweka’s attempted pass was blocked, with the ball falling to the forward who slotted past Will Dennis.
Almost immediately after, Slough were dealt a blow with Francis Amartey pulling up with an injury, the striker eventually replaced by Ogo Obi.
Slough had their first chance of the game in the 13th minute with Obi having an effort from just inside the box however the forward was unable to generate any power on it.
Slough had another chance to equalise a minute later after James Dobson whipped in a brilliant ball to Elliot Benyon, whose header went agonisingly past the post.
In the 21st minute, Matt Lench had an effort from distance which flew over Myles Roberts’ crossbar.
Welling United doubled their lead on 34 minutes after Ade Azeez knocked the ball down to Alexander, who twisted and found the top corner from close range.
There was nearly an instant response from the Rebels as Josh Jackman curled an effort which struck the post, with Benyon unable to convert the rebound with the ball being blocked on the line.
George Alexander completed his hat trick in the 37th minute after a defensive mix-up involving Scott Davies and Will Dennis allowed the striker to intervene and complete his hat-trick.
Slough started the second half looking for a way back into the game as Dobson and Johnny Goddard both had strikes in the 53rd minute that were cleared away by the Welling defence.
James Dobson had a golden chance in the 59th minute after Louis Walsh – a half-time replacement for Davies – got the ball down the left hand side, cutting inside and drifting past a few Welling players before laying the ball off to Dobson, whose strike from close range flew over Roberts’ crossbar.
Just past the hour mark, Louis Walsh went close with a blistering effort aimed at the top corner from outside the box, but Roberts did well to push the ball past the post.
There was a goalmouth scramble in the 68th minute as Slough had an effort cleared off the line before Benyon’s header was punched away by Roberts.
Temi Eweka had a chance in the 78th minute after he found himself unmarked in the Welling box thanks to a clipped ball in from debutant substitute Moe Shubbar, but the defender was unable to get his strike off quick enough as Myles Roberts made himself big to deny the Slough man.
Moments later, Obi headed wide from a Lench cross when it looked certain he would hit the target.
The Rebels pushed for a way back into the game, however Slough came up short whenever in the final third with defensive mistakes and clinical finishing the difference between the two sides.
After this first home defeat in 2023, Slough will now look to reverse their fortunes in Tuesday evening’s clash away at Dartford.
Image: George Beck
Welling United Line up
Myles Roberts, Rob Howard, Taylor Furron, Medy Elito, Kodi Foster, Ade Azeez, Amadou Kassarate, Jamie White, Aaron Powell, Taylor Maloney, George Alexander. Substitutes: Manny Parry, Kyrell Lisbie, Kai McKenzie, Cameron Andrews, Aaron Barnes.