He scored the winning goal with two minutes remaining. The score was 1-all at halftime and Miles John scored his first league goal of the season for the Blues in the first half.
"Miles was always a threat. We brought him up higher so he could play at right midfield or right forward," Robertson explained.
"While the score does not do justice to our performance we know our execution, in terms of finishing, could be better. It's only a matter of time until we get more goals and that's a good sign two weeks out from a Chatham Cup final," Robertson said.
Petone defended deep as they did when they beat Napier 1-0 at Bluewater Stadium on May 24.
The Blues will play Auckland's Eastern Suburbs in the Chatham Cup final on September 20 in Auckland. Robertson pointed out his troops will have a big training schedule before travelling north.
"We're always looking to improve ... that's a big focus for us. We'll do our homework on Eastern Suburbs and come up with a plan we think will benefit us. Finishing will be just one of the work ons we deal with," Robertson added.
If Rovers capture the Chatham Cup, the most prestigious football trophy in the country, it will be the fifth time in the club's 42-year history " the last in 2002.