Crusaders captain George Whitelock lamented his charges' performance against the Rebels yet was thankful for Tom Taylor's accurate goal-kicking.
The New Zealanders limped to a 30-26 victory over the Australians in a win that moves them up to seventh overall and third in their conference.
And despite four points being banked, Whitelock was left unhappy with his side's defensive effort as they leaked three tries in Sunday's fixture.
"We started well but then we took the foot right off the throat and let the Rebels right back in. Our defence was pretty passive," he said, adding that the message was clear when the Rebels led with 20 minutes remaining.
"We needed to work away and wear them down and we eventually got the penalties."
The Crusaders will take on the pace-setting Brumbies at Canberra Stadium next Sunday.