Guest yesterday led a dynamic display from the much-changed Aviva Premiership champions, who progressed via Matt Hopper’s try and 11 points from Ben Botica.
“In the second half we just ground it out,” Guest said after Quins’ 10th successive victory. “We are on a massive winning run. The young guys played their hearts out and it’s a great achievement and gives us confidence for the semi-final.”
Ernst Joubert’s try and 17 points from Ben Spencer gave Saracens a 22-12 win at Worcester on Saturday and set up a last-four trip to Sale.
London Irish lost 10-6 to Cardiff Blues on Friday, while Wasps and London Welsh also suffered defeats, to Sale and Newport Gwent Dragons.
The LV= Cup. Watch the next generation break through. For tickets and info, visit www.lv.com/rugby