**Ulster and Benetton were the only Guinness PRO14 sides to advance to the European Rugby Challenge Cup quarter-finals after a weekend filled with drama in the last 16.** Ulster will play Northampton Saints in the last eight next Saturday after a thumping 57-21 victory over Harlequins at The Stoop. The Irish province ran in four tries in the first half and four in the second as they overwhelmed a young and inexperienced Quins side.