Josh Stephenson and Tom Biss propelled wind-assisted screamers from about 30m out to the top right-hand corner of the goalmouth in the space of two minutes in between Kilkolly's goals.
Greatholder also was delighted to have offered valuable minutes to Ross Willox and Vinnie McKirdy off the bench.
"It's good for the future of the club," he said, delighted with the top-rung perch after just four rounds into the league.
Defending champions Rovers are the only undefeated side left in the league after Miramar Rangers dislodged leaders Stop Out with a 2-1 win and Western Suburbs thrashed Wellington United 6-1.
"We were under the pump a little and it hasn't been easy with tough fixtures, so if someone had said before the season we'd be on the top after four rounds we'd have been very happy," Greatholder said, mindful they would have their marquee player/coach Bill Robertson, defender Fergus Neil and midfielder Saul Halpin back from Team Wellington, who lost 3-0 to Auckland City, in their O-League final on Saturday.
In the other game on Saturday, Lower Hutt City held hosts Palmerston North Marist 3-3 at Memorial Park while Wellington Olympic did the same thing, by the same margin, to Wairarapa United at Memorial Park, Masterton, yesterday.
The Blues will host Marist at Park Island this Sunday in a 2pm kick-off.