Champions Alloa saw their seven-game winning run come to an abrupt end as they were thrashed by play-off chasing Berwick Rangers.
Berwick are now six points off the final play-off spot after a stunning performance.
Danny Handling opened the scoring in the 13th minute, firing into the bottom right-hand corner of the net from the edge of the area.
A minute later it was two as Lee Currie got on the end of Handling's flick-on to fire in from six yards.
It got worse for Alloa when defender Ryan Harding turned the ball into his own net in the 34th minute.
The Black and Gold scored their fourth six minutes after the interval as Handling converted his second from close range.
And the home side made it five in the 58th minute when Stuart Noble found the top corner of the net from 12 yards out.
Berwick: Bejaoui, Notman, McLean (Walker 75), Forster, McGlinchey, McDonald, Greenhill (McLaren 61), Currie, Ross Gray, Noble (Miller 61), Handling. Subs Not Used: Barclay, Ferguson.
Booked: McLean, Forster.
Goals: Handling 13, Currie 14, Harding 34 og, Handling 51, Noble 58.
Alloa: McDowall, McCullagh, Harding, Michael Doyle (Gordon 38), McKinnon, Ryan McCord, Masterton, Docherty, Ross McCord (Wright 54), May, Campbell (Cawley 54). Subs Not Used: Bain, Philp.
Ref: Euan Anderson