Mahe Fonua scored one of the easiest tries of his life to open the scoring for the Black and Whites, crashing over out of dummy half and catching the Saints defence napping.
St Helens scored their second try in three minutes courtesy of Matthew Fleming, who touched down in the same corner.
Owens nailed the conversion to give the Saints a 10-6 lead with just under a quarter of an hour remaining.
An Owens penalty ensured the Saints restored their eight-point lead over the Black and Whites.
Vea looked to have sealed victory for the Saints, crashing over under the sticks after the Airlie Birds failed to deal with James Roby’s grubber kick.
A Jordan Turner drop goal continued to put further distance between the two sides.
Owens added insult to injury scoring another four-pointer with four minutes left, following a pass from Theo Fages.