Josh Cohen completed the rout with the goal of the game - a flowing 25-passing move.
A delighted Lewis told JC Sport: "We were in cruise control from the off - it was a matter of how many today.
"We’re building up some momentum now and will be looking to go into the Xmas break with yet another win against Oakwood."
Scrabble boss Ray Abrahams praised his players for their efforts, and told JC Sport: “The Galaxy manager’s pre-match comments without doubt came back to haunt him, as they did not manage to put our goal difference into orbit and after saying 5 would be a disappointment we kept it to exactly that.
"However, for the second game in a row, against top quality opposition, we acquitted ourselves very well and I was proud of each and every player for the way we went toe to toe with them and gave everything.
"We even had to battle with just 10 men for half an hour after our striker Ben Nassim was sent off. Such was our passion and incredible commitment from our boys considering our league position."
Scrabble had given a good account of themselves, restricting Galaxy to a one-goal lead. But the floodgates opened to the tune of four second-half goals. But Abrahams was quick to pick out some positives.
"At half time we were confident of pulling off a shock result and maybe taking something from the game, even the three points. But we conceded early in the second half and that gave us a real uphill task.
"Our keeper saved a penalty but they scored from the rebound and we gifted them two easy goals when we failed to clear the ball from our goal area.
"If we keep working hard and continue to give it a go like we did today then there’s no question that results we need will come for us.”
GALAXY: James Belchack, Daniel Brennan, Josh Cohen, Ozzy Doron, Adam Feldman, Jordan Grundman, Jamie Murray, Zack Nathan, Bailey Snow, Jess Alexander, Luke Lewis. Subs: Josh Buchardt, Jordan Freeman
SCORERS: Lewis 2, Alexander 2Cohen
SCRABBLE: Josh Molloy, Jason Bharier, Eli Gottlieb, Jeremy King, Ben Nassim, Tshero Raphael, Oliver Richardson, James Rodney, Jeremy Teacher