The neighbour spotted two cars there and noted down the number plate, managing to only get part of the other one, then called the police as the burglars screeched away.
Police said the theft was reported at 4.51am, and the jetski was found at 4.54am.
It was undamaged and was able to be returned to the owners.
Paula said her son was at the house when the burglary happened, but didn't wake up until police arrived. He called his parents to tell them about the incident.
Paula said it happened on her husband's birthday, making the return of the jetski an unexpected birthday gift.
"If nobody had noticed them taking it it would have disappeared."
She and her husband took a bottle of wine over to their neighbour to thank her.
Paula said police were "awesome" and "really on the ball that day".
"It's a good thought knowing you can get a reaction time like that."
The couple have increased the security in their yard.
Paula said the incident "gave us a bit of a fright" but the quick response made them feel "a lot better about it".
She did not know why the burglars decided to commit the crime but hoped they could get their lives "back on track".
One person has been charged over the burglary.
Anthony Whiting, 28, appeared in the Porirua District Court today where he pleaded guilty to burglary, but not guilty to a related charge of driving while disqualified. His lawyer said Whiting was not alone when he committed the crime.
Judge James Johnston remanded him on bail to a case review hearing in April.