The Blues' next assignments are against the Kings in Port Elizabeth and Lions in Johannesburg. Umaga's men should beat the Kings, one of the worst teams in the competition, but they can't afford to fall into another trap of their own setting.
Complacency shouldn't be an issue given the Blues haven't won a competition game away from Auckland in almost 24 months, but it might be worthwhile Umaga showing his side the second half of last night's match once they arrive in South Africa.
There was a new, direct attitude to the Blues at the start of this game and it appeared to be all but over after 30 minutes when Ihaia West scored his try thanks to Steven Luatua's catch of his re-start and Patrick Tuipulotu's charge up the middle.
West did well to prop off his left foot and go through traffic to score by the posts, but it was the lead-up from the Blues' big men which paved the way, and they did so most of the night.
West's try was the fourth consecutive five-pointer for the Blues.
They had an untidy start to the half when the Rebels' Reece Hodge scored, but otherwise were in control, although the Rebels' second try on the stroke of halftime, by Jordy Reid, should have set off a few alarm bells.
Umaga has had to endure too many close finishes for his liking since taking over the franchise at the start of the season.
One of his hopes yesterday was that his team would be able to shut out the visitors early. They got to the first part right but the second part, holding or extending that lead, remains a work in progress.
Too often this season the Blues - who lead the statistics in terms of retaining possession - have pushed passes across the park in the hope that something good happens. Not this time. Their first three tries were scored by forwards as the home side kept it tight.
The Rebels' second-half comeback saw tries from Colby Faingaa and Sefa Naivalu, the last of which denied the Blues their first winning bonus point of the season. It was a reminder that this Blues team contain a fair bit of talent, but are still lacking a ruthless edge.