Ulster ran in eight tries at The Stoop as they booked a place in the last eight of the European Challenge Cup with a comfortable win over Harlequins.
Having opted to play a young, weakened side, the Premiership side were torn apart by their Irish Pro 14 opponents.
Hooker Rob Herring and flanker Sean Reidy crossed twice, one in each half.
Centre Stuart McCloskey and full-back Michael Lowry also went over in the first half, bolstered by Billy Burns and Albie Mathewson after the break.
That booked a quarter-final trip next Friday night to Northampton, who won a 43-39 thriller in south Wales with Dragons the day before.
Quins' three tries came from captain Tom Lawday in the first half, then fellow back-row forward Jack Kenningham and late replacement Jordan Els.
John Cooney kicked five conversions and an early penalty for an individual 13-point haul for Ulster, supplemented by two late conversions for Ian Madigan.
In their first-ever game in the European Challenge Cup, the Irish side maintained their dominance over Quins, having now won six of the eight meetings the two sides have shared in European competitions.
But it was always likely to be that way once Quins, who stand fourth in the Premiership, opted to save most of their regular first-choice line-up for league duty.
They ended up on the wrong end of an embarrassingly large defeat by the Pro 14 group runners-up, whose league season ended 16 days earlier. Even when captain Jordi Murphy was yellow carded, Ulster still ran in the try of the game from Lowry.
Maul the key to big win - McFarland
Ulster head coach Dan McFarland on BT Sport: "Our maul went really well and on a weekend where there were tries all round, I thought to restrict them to three tries was actually quite a success because they're a really good attacking team.
"[Forwards coach] Roddy Grant has done a really good job on the forwards, in the Pro14 this year we've had a lot of success in our line-out and our line-out defence and our maul.
"We needed to find a hammer in some aspect of the game that was going to put them under the cosh and the maul was it."
Harlequins: Green; Northmore, Lang, Lasike, Earle; Herron, Steele; Garcia Botta, Elia, Collier, Tizard, Hammond, White, Kenningham, Lawday (capt).
Replacements: Head, Els, Kerrod, Cavubati, Jurevicius, Stafford, Tapuai, R Chisholm.
Ulster: Lowry; Baloucoune, Hume, McCloskey, Stockdale; Burns, Cooney; O'Sullivan, Herring, Moore, O'Connor, Treadwell, Reidy, Murphy (capt), Timoney.
Replacements: Andrew, Warwick, O'Toole, Izuchukwu, Rea, Mathewson, Madigan, McIlroy.
Referee: Romain Poite (France).