Shamrock Rovers inflicted UCD's heaviest defeat of the season to plunge the Students back into the relegation place on goal difference.
The Students went into the tie in the play-off spot, six goals ahead of Finn Harps, but quickly saw that advantage evaporate as Rovers ran riot.
Aaron McEneff and Aaron Greene each scored a brace, while Graham Cummins, Dan Carr and Jack Byrne were also on target, as Rovers warmed up in style for their Europa League date with Apollon Limassol.
UCD, meanwhile, came crashing back to earth following the euphoria of Monday night’s victory over Bohemians that had extended their recent run to seven points from nine.
While it looked as if the torrential rain that showered the faithful at Portrush had spared the citizenry of Tallaght, the heavens duly opened upon kick-off and the game was scrappy.
Cummins had a glorious opportunity to open his Rovers account inside three minutes as Dylan Watts flashed a ball across the face of goal but the on-loan Cork City striker couldn't connect.
Dan Carr saw his header from the outstanding Watts’ cross well-saved by Sheridan but the keeper, who’s just home from the World University Games, should have done better for Cummins’ opener.
It arrived after 13 minutes when Byrne’s through ball was handily deflected into his path and his powerful shot beat Sheridan at the near post despite the keeper getting a hand behind it.
Rovers began to find the fluidity that underpinned their comeback win over Brann in the Europa League on Thursday and it took a fine challenge from Dan Tobin to deny Carr from Watt’s cross.
The striker looked to foul Tobin in the process but a corner was given and UCD were made to pay as McEneff glanced Byrne’s cross into the far corner of the net.
Two more goals followed inside four minutes as the Students collapsed, Carr touching home Sean Kavanagh’s cross to make it 3-0 with Cummins also lining up for the tap-in.
If that goal was soft, there was nothing the Students could have done about the fourth as Byrne showed supreme balance and skill to drift into the box and hammer a shot past Sheridan.
Byrne, whose outstanding finish prompted Thursday’s comeback against Brann, left the field on the hour to a standing ovation.
By that stage, the Hoops were 6-0 up as Greene, a half-time replacement for Cummins, took less than two minutes to tee up McEneff to walk the ball into an empty net.
And the striker got in on the act himself as the hour approached when he nodded home from close range following an excellent run and cross from Sean Kavanagh.
Sheridan formed a one-man rearguard action in the final half hour with outstanding saves to deny Byrne, Watts and Carr.
Carr himself passed up a chance to make it seven when he hit the bar from point-blank range, but Greene brought up his double when he robbed Evan Farrell before slotting home.
Shamrock Rovers: Alan Mannus; Ethan Boyle (Eric Abulu 46), Roberto Lopes, Lee Grace, Sean Kavanagh; Gary O’Neill, Aaron McEneff, Jack Byrne (Thomas Oluwa 59); Dylan Watts, Dan Carr, Graham Cummins (Aaron Greene 46).
UCD: Gavin Sheridan; Dan Tobin, Harry McEvoy, Evan Farrell; Richie O’Farrell (Isaac Akinsete 75), Jack Keaney, Paul Doyle, Jason McClelland, Mark Dignam; Dara Keane (Jack Ryan 65), Yoyo Mahdy (Danu Kinsella Bishop 46).
Referee: Ben Connolly.