The Vikings took an early lead when Marsh went over the line after nine minutes, but missed the resulting conversion.
Saints hit back through Samoan Meli, as he grabbed a try on 17 minutes, before
Gaskell missed following kick.
The sides went in level at the break before Saints stormed ahead with Gaskell adding a try of his own on 68 minutes and made no mistake with the resulting kick.
Meli then added his second two minutes later with Gaskell once again converting.