In fact many of the crowd would have been excused if they thought Rovers had won the league yesterday such was the extent of right forward Wesley Cain's celebrations after the hosts opening goal in the 14th minute.
Canadian Cain did three consecutive back flips after a superb solo effort.
"Wes was a pretty handy gymnast in his younger days. We give him the freedom to roam and as a result of that freedom he gives us the results we want. We build a game plan around him," Robertson said.
Cain set up the other two goals for prolific Uruguayan striker Martin Bueno. The first came in the 42nd minute after a corner and this gave the Blues a 2-0 lead at the interval.
Former Blues striker Angus Kilkolly scored Rangers' only goal from a penalty in the 49th minute. More classy buildup work from Cain gave Bueno the final goal of the game in the 87th minute.
Close behind Cain in the tussle for Blues player-of-the-match honours was keeper Ruben Parker Hanks. Rangers had 11 shots on goal and eight corners but Parker Hanks was rock-like as he was regularly pounded.
"There were a couple of big saves from Ruben when he was put under pressure. They allowed us to build our platform. Now we're back on the top we have to stay there ... we have to build on this momentum," Robertson added.
Robertson and fellow experienced centre back Danny Wilson marshalled Rovers defence well. Promising centre midfielder Karan Mandair was thirsty for work and Japanese left forward Sho Goto often got the better of the Rangers defence.
Rangers deserve praise for their positive approach to an entertaining battle. Midfielder Taylor Schrijvers had a huge workrate.
■ Building King Havelock North Wanderers kept their hopes of avoiding relegation alive with a 4-2 win against Wellington United in ideal conditions at Guthrie Park on Saturday. Waterside Karori's 2-1 loss to Wellington Olympic also worked in Wanderers favour.
The Ethan Dent-captained Wanderers led 2-1 at halftime against the youthful fourth-placed visitors despite conceding a rash of silly fouls. Wanderers meet Rangers away next weekend and Rovers host Olympic.