Saracens set up a Pool Four showdown with Biarritz for a place in the Heineken Cup quarter-finals after bagging five points against Treviso.
HEINEKEN CUP POOL FOUR
Saracens: (32) 35
Tries: Scarbrough, Harris, Yates, Bartholomeusz
Cons: Jackson (3)
Pens: Jackson (3)
Treviso: (21) 30
Tries: Goosen, Williams
Pens: Goosen (5)
Dan Scarbrough, Dan Harris, Kevin Yates and Mark Bartholomeusz touched down for the hosts, while fly-half Glen Jackson kicked 15 points.
South African fly-half Marius Goosen spearheaded Treviso's challenge with a solo try and a 22-point haul.
Saracens must beat Biarritz to reach the knockout stages for the first time.
However, Saracens, who lacked cohesion against the plucky Italians, will have to improve markedly if they are to trouble the French giants.
Treviso took only four minutes to open up Saracens' defence, Goosen running straight through Ben Johnston and Thomas Castaignede.
He converted his own try before Saracens' Scarbrough restored their lead with a try in the right corner and Jackson added the extras.
Treviso edged back into the lead with two quick-fire penalties before Ben Skirving and Jackson combined to set up Harris to score.
Treviso replied with a try from Williams, who collected his own chip-and-chase, but Jackson restored parity for the hosts with a penalty shortly after.
Kevin Yates then crashed over and Jackson converted, but a drop-goal by Stuart Legg kept Treviso in touch at 25-21.
Saracens entered the break with an 11-point cushion, however, when Scarbrough collected Jackson's cross-field kick and offloaded in the tackle to Bartholomeusz.
After the break, Treviso had substitute hooker Fabio Ongaro sin-binned for diving in at a ruck but Saracens could not make the breakthrough despite their numerical superiority.
Treviso actually shaded the game in Ongaro's absence, finishing the 10 minutes with another Goosen penalty.
Jackson missed a late drop goal and Saracens were forced to defend a late five metre scrum before holding out for victory.
Saracens boss Steve Diamond:
"This result has helped our confidence but we go from hot to cold which isn't acceptable. We have to learn how to kill games off.
"We will have to play at 100% for 80 minutes to stand a chance in Biarritz next week. But I'm just glad to get all five points and it set up."
Saracens: Bartholomeusz; Scarbrough, Castaignede, Harris, Johnston; Jackson, Dickens; Yates, Byrne, Broster, Vyvyan (capt), Chesney, Randell, B T Russell, Skirving
Replacements: Cairns, Liffchak, Kyriacou, Seymour, Raulini, Bailey, Sorrell.
Treviso: Williams; Perziano, Legg, Barbini, Dallan; Goosen (capt), Picone; Sbaraglini, Tejeda, Mazino; Pavanello, Wentzel; Dal Maso, Orlando, Wium.
Replacements: Ongaro, Allori, Gritti, Pavanello, Palmer, Troncon, Marcato.