The challenge trophy in the league has been around for four decades with the Rovers first getting their mitts on it in 1997.
The Blues won it in the 2011 league when they beat Miramar 2-0 before losing it 3-2 to Petone the following year.
The Rovers lost the shield last winter.
Yesterday, midfielder Tom Biss opened the account in the 31st minute against the Wiremu Patrick-coached Rangers, latching on to the ball at the back post it was crossed from the right flank to volley it past goalkeeper Charlie Morris.
But the day belonged to teenage Angus Kilkoly who scored a hattrick of goals (55th, 71st and 88th).
"We're asking Gus to play a different role out wide as a right forward and he's still scoring goals," he said of Kilkolly who also scored a hattrick last winter.
Robertson said there was predictably a little bit of wind at the venue but it didn't have much bearing on the game.
"We dominated the first half and scored in the second so tried to kill the game.
"We took our foot off the gas a little bit by sitting back and making counterattacks."
Robertson will jet off with Team Wellington to Fiji on Thursday for their O-League campaign.
The Wellingtonians sweated a little on Sunday as Hawke's Bay United looked like beating Oceania League campaigners Auckland City in the ASB Premiership final at Kiwitea Street.
The Blues had Bay United equal golden-boot winner Ryan Tinsley as the only change to their line-up yesterday.
Player/assistant coach Chris Greatholder will be at the helm when the Napier side play Lower Hutt away this Saturday and, if Team Wellington make the playoffs in Suva, he will remain coach against Tawa at Park Island, Napier, on Sunday, April 18.