The English hosts ran in six tries, four of which emerged in the first half to lay the foundation for victory with a 26-8 half-time lead.
Province produced a spirited start to match and Saracens were straight away forced on to the back foot as their defence was called into early action in their own 22m area.
The effort earned Province a third minute penalty and flyhalf Demetri Catrakilis goaled from virtually in front of the Saracens posts (3-0).
Straight from the restart, Saracens imposed themselves on the match over a 15-minute passage of play, and the much vaunted Province defence were stretched to limits as they conceded two tries in quick succession.
Saracens wingers Chris Ashton and David Strettle each scored a try when they found space out wide to round the defence.
Flyhalf Charlie Hodgson was on target with one attempt and after 19 minutes’ play, Saracens enjoyed a 12-3 lead.
Somewhat against the run of play Province launched a powerful surge down the left flank.
Catrakilis was put in possession some eight metres from the tryline and he managed to corkscrew his way out of several tackles for his side’s first try.
Both conversion attempts failed after the referee ordered a retake following a premature charge by Saracens on the first kick (12-8).
The class in Saracens’ ranks started to count in the play leading up to the half-time break and two more converted tries saw them end the first half with a comfortable 26-8 lead.
Ashton snatched a second try and the South African-born lock Mouritz Botha scored Saracens’ fourth try after a fine finishing burst down the right hand touchline.
In the opening minute of the second half an upfield surge by Province with fine inter-play between backs and forwards undid the defence and Catrakilis dived over for his second try and he added the conversion (26-15).
Three minutes into the second half, Province brought on new cap Bongi Mbonambi, Louis Schreuder and Kurt Coleman as replacements for Scarra Ntubeni (hooker), Nic Groom (scrumhalf) and Catrakilis respectively.
Hodgson goaled two penalties in as many minutes and going for the posts at this stage of the match suggested that Saracens committed to putting the final result beyond the Cape Town visitors (32-15).
Once Saracens braved the Province pressure the bounced back in telling fashion with a counter-attack down the right flank before Strettle ran in his side’s fifth try, with Hodgson converting.
The Province newcomers prop Wilco Louw and Mbonambi ran the Saracens defence ragged in a concerted attack down the centre before the latter dotted down for Coleman to convert (39-22).
Two Saracens replacements produced the final scoring in the match some eight ahead of the final whistle when Will Fraser grabbed try number six and Ben Spencer raised the flags with the conversion (46-22).
Saracens: Tries: Chris Ashton (2), David Strettle (2), Mouritz Botha, Will Fraser. Conversions: Charlie Hodgson (4), Ben Spencer. Penalty: Hodgson (2).
Western Province: Tries: Demetri Catrakilis (2), Bongi Mbonambi.
Conversions: Catrakilis, Kurt Coleman. Penalty: Catrakilis.