Central defender Dan Cleary scored twice to top and tail a comfortable victory for Dundalk at the UCD Bowl to edge the champions another step closer to retaining their title.
Dundalk are now unbeaten in 19 league games, 24 in total against domestic opposition as they remain four points clear at the top of the SSE Airtricity League Premier Division table with tow games in hand.
A sixth straight league defeat leaves UCD six points adrift at the foot of the table, and they've now played a game more than second from bottom Finn Harps.
One of three changes from their 3-0 defeat at Oriel Park on Monday, Conor Kearns returned in goal for UCD following his lengthy suspension.
Dundalk boss Vinny Perth showed the depth of his squad with seven changes as they expectedly dominated from the off.
College skipper Liam Scales deflected a Patrick McEleney drive out for a corner on four minutes to signal the onslaught on the home goal.
Nine minutes later Dundalk were duly in front from their third corner of the game from Sean Murray.
Whipped in to the near post, the delivery was met by the unmarked Cleary who powered his header past Kearns.
Murray forced Kearns to bat his shot out for another corner three minutes later after he’d nicked the ball off a sluggish Jack Keaney.
Again Murray took it, this time picking out Cleary’s central defensive partner Sean Hoare, once more negligently marked, who planted his header to the net.
Jason McClelland lifted the siege on 21 minutes, seeing his left-footed drive flash narrowly wide, as UCD began to enjoy spells of possession.
But the home goal was fortunate not to concede a third goal in the minutes before the interval.
First Luke Boore did well to block Georgie Kelly’s shot on the turn to concede yet another corner.
Murray’s ball in led to a right scramble with UCD defender Harry McEvoy happy to see Kearns push the ball away to prevent an own-goal.
McEleney then shot wide from a Robbie Benson free kick routine right on 45 minutes.
Some trickery from Liam Kerrigan flummoxed McEleney to bring UCD a chance 12 minutes after the interval, though his shot was off target.
While Dundalk continued to have plenty of the ball, they laboured to create much in front of goal until the 70th minute when they extended their lead.
Michael Duffy was sprung from the bench and immediately invigorated the visitors' attack.
Four minutes after his introduction, the winger skipped through the inside left channel to rifle a shot past Kearns at his near post.
Georgie Kelly added Dundalk fourth goal on 90 minutes, looping a header past Kearns from Cleary’s cross.
Cleary then had the final say two minutes into added home with a near post headed finish from Duffy’s corner.
UCD: Conor Kearns; Harry McEvoy, Liam Scales, Luke Boore, Evan Farrell; Jack Keaney, Dara Keane (Richie O’Farrell 81); Liam Kerrigan, Yoyo Mahdy (Ciaran Behan 75), Jason McClelland; Sam Byrne.
Dundalk: Gary Rogers; Cameron Dummigan, Dan Cleary, Sean Hoare, Dane Massey; Chris Shields, Sean Murray (Michael Duffy 66); Daniel Kelly (Patrick Hoban 76), Patrick McEleney, Jamie McGrath (Robbie Benson 30); Georgie Kelly.
Referee: Ray Matthews (Longford).