Northampton overcame the loss of injured captain George Furbank to post a statement 30-21 Investec Champions Cup win against the Bulls in Pretoria.
England international full-back Furbank went off 10 minutes before half-time after suffering an issue with his right arm following a tackle by Bulls skipper Elrigh Louw.
The Gallagher Premiership champions dug deep, though, at Loftus Versfeld, with Furbank’s replacement George Hendy and number eight Juarno Augustus scoring first-half tries en route to a bonus-point triumph.
Augustus’ score came immediately after Saints prop Emmanuel Iyogun had been yellow-carded, which underlined a resilient performance at altitude in temperatures of more than 30 degrees.
Wing Tommy Freeman added two tries after the break, while fly-half Fin Smith kicked two conversions and two penalties. Back-row forwards Cameron Hanekom (two) and Marcell Coetzee touched down for the Bulls, with Johan Goosen converting all three.
Saints’ victory leaves them in charge of Pool Three following a bonus-point success against Castres in their Champions Cup opener.