"I just can't add it up in my head," said a bemused Shelbourne manager, Dermot Keely, after his side's latest bad result at the Carlisle Grounds on Saturday night.
Shelbourne totally controlled the first half, missed several clear chances, only to lose to a 66th minute goal from Jason Byrne.
Having started the season as main title contenders, Shelbourne are already nine points behind joint leaders St Patrick's and Cork City as they slumped to their lowest league placing since winning the title seven years ago.
Frustrated by not having seen their team win in six matches, already there were chants of "we want Keely out" from a small section of the Shelbourne support at the finish.
Shelbourne should have had the match won by half-time but for the referee, Bray goalkeeper, Alan Kane, and a bad miss by Dessie Baker.
Referee Paul McKeon disallowed a Pat Scully-headed goal from Pat Fenlon's eighth-minute corner for pushing as Shelbourne threatened to over-run a Bray side.
Shelbourne dominated with Kane producing an excellent save from a Fenlon header on 27 minutes while, a minute later, he knew very little as he got his body in the way of another header from Scully.
The only goal came on 66 minutes when Shelbourne fell asleep at a throw-in. Byrne burst through to score from 16 yards.
Bray Wanderers: Kane; Tresson, Lynch, McKeever, Keogh; P O'Brien, Dodd, Fox, Smyth; Byrne, Ryan.
Shelbourne: Gough; Neville, Scully, McCarthy, D. Geoghegan; R. Baker, Costello, Fenlon, Heary; D. Baker, Morley. Subs: Gifford for Neville (half-time).
Referee: P McKeon (Dublin).