The Crusaders also lacked urgency in their previous match against the Reds in Christchurch, but they ground out a victory despite falling behind straight from the kick-off and failing to score any tries in the 15-11 win.
Last night, although they fought back to take a 19-10 halftime lead and appeared to look comfortable, they were affected by the same malaise after the break and failed to fire a shot.
When they were forced to chase the game they were harried into mistakes by the Rebels and, given their first instinct when presented with the ball recently has been to kick, they looked desperately short of form and options among their backs.
Tom Taylor, who kicked five from five, was substituted in the second half, but Dan Carter, who again started at second-five didn't have the option of a kick at goal.
All Blacks' captain Richie McCaw, who started for the Crusaders for the first time this season, said his team needed to start better.
"They're a team [Rebels] that needs to start well and we allowed them to do that," he said. "The first 20 minutes, they came out and played well and also defended pretty well. They grew an arm and a leg as the match wore on."
The result will have lifted New Zealand teams the Hurricanes and Highlanders who will fancy their chances of overtaking the Crusaders into second spot behind the Chiefs on the local conference.
The quality of rugby in Dunedin was of a higher order, with the Hurricanes winning a topsy-turvy match 26-20.
A try from wing Julian Savea sealed it for the Hurricanes after the Highlanders controlled the first half, leading 17-9 at one point.
"It was just those little things that let us down," Highlanders' captain Andrew Hore said. "A couple of missed throws and turnovers at scrum time."
The Blues earned only their second win of the season against the Johannesburg-based Lions 25-3 at Eden Park, but it is the South African teams who are making their move on the Super Rugby table.
Three teams from the Republic occupy top six places following wins by the Bulls, Stormers and Sharks.
The Bulls, expected to struggle on their Australasian tour, beat the Waratahs 27-24. The Stormers maintained their good form with a 16-14 win over the Cheetahs in Cape Town and the Sharks thrashed the Force 53-11 in Durban.
New Zealand's top team the Chiefs play the Reds in Brisbane tonight.