Francesca McGhie got Trailfinders off the mark inside three minutes but visitors Saracens replied quickly, going level with a score from Sydney Gregson.
With relentless attacking play, Saracens turned their trailing start into a 26-point half-time advantage with further tries from Marlie Packer, Alysha Corrigan, Lotte Sharp and Campbell.
There was no respite for the hosts as Poppy Cleall put Saracens further ahead after the break, finishing off a driving maul to make it 36-5.
Campbell scored her second of the game before ex-Trailfinders prop Liz Crake added to her former side’s difficulties with Saracens’ eighth try.
There was time enough for Jess Breach to have her say and the world champion finished a blistering counter-attack in the final minutes to give Saracens a convincing 57-5 win.
Exeter Chiefs settled for their second draw of the season away at Sale Sharks‘ Morson Stadium, where a battling contest ended 26-26.
The teams scored two tries apiece in the first half, which the visitors ended with a narrow 14-12 lead.
Chasing their second win of the season, Sale opened up a 12-point advantage after the break with tries from Gwen Pyrs and Morwenna Talling.
But a yellow card allowed Exeter back into the game, as a converted try scored by Emily Robinson put the visitors back within touching distance while Sale lock Charlotte Fray was in the sin bin for a high tackle.
In the end, the game was decided from the tee. With Sale 26-21 up, World Cup winner Holly Aitchinson passed up a chance to extend their lead by missing a penalty with 10 minutes to play.
Hope Rogers crossed to bring Chiefs level, and so it stayed after Exeter missed the extras. Given a second chance to nudge Sale ahead at the death, Aitchinson missed a penalty in added time and so the teams were tied at the whistle.