His try inside a minute of the start of the game was the first of two for the Quins' wings. Ugo Moyne grabbed the other try and All Blacks outside half Nick Evans marked his debut with 11 points. Fijian replacement Waisea Luveniyali completed the scoring with a penalty.
Strettle found himself demoted to the England Saxons squad by Johnson in the wake of the ill-fated New Zealand tour, but the try was just the tonic he needed to start his season.
Saracens also ran in two tries and featured 2005 Lion Michael Owen at No 8 for the first time and had England veteran Steve Borthwick making his debut at lock.