But they had to dig deep to edge past a spirited Inverness team who are well worthy of their place in the top flight.
Home player/boss Craig Brewster twice guided his side to draws against the champions last term at Pittodrie and Ibrox. However, this was Rangers' first ever trip to Inverness.
Both teams began their SPL seasons with wins seven days previously - the Caley Jags at Falkirk and the Gers against Livingston in Glasgow.
Full-back Ross Tokely returned for the Highlanders in place of young David Proctor, while the visitors' starting line-up was unchanged.
Alex McLeish's side began brightly, with Thomas Buffel and Alex Rae pulling the strings in midfield, while a few stray passes were letting down Brewster's boys.
While Rangers continued to create the best half chances, the Inverness side looked a threat when they launched attacks.
Brewster came to the rescue on his own goal-line after 25 minutes to clear new man Jose Pierre FanFan's effort out for a corner when it seemed certain to find the net.
The Caley Jags almost grabbed the lead after 33 minutes, but Brewster failed to get a shot in from close range. Then Ronald Waterreus brilliantly dived to save a Darren Dods header from a Barry Wilson delivery in the aftermath.
In the dying moments of the first half, the Gers keeper had to get down to block a Brewster drive. Then they were relieved when referee Calum Murray waved away strong appeals from the north crowd when Tokely went down under a challenge in the penalty box.
There was much end-to-end drama in the second half, with no quarter given by any of the players. Nacho Novo and Stuart Golabek tested their respective opposing goalkeepers.
Out of the blue, Rangers went in front after 69 minutes when Ferguson kept his cool to divert the ball beyond Mark Brown from a cross from the right flank.
Caley Thistle threw everything forward in the closing stages, but they could just not find an equaliser which they would have so richly deserved.