Three tries in the final 10 minutes made the scoreline more flattering for the Storm in their Sunday encounter in Casey in outer south-east Melbourne, with the Cowboys otherwise outclassing the 2024 grand finalists.
"I thought our first 60 minutes was quite mature, we controlled the ball well, put the ball in the corners, but I was disappointed in that last 10 to 15 minutes," Payten told AAP.
"We were a little bit loose and defence on our try line not good enough, so yeah, a bit to work on."
Fullback Scott Drinkwater bagged two tries, while young halfback Thomas Duffy looks certain to make his NRL debut in round one after an impressive showing.
"He's had a great pre-season, he's had a great apprenticeship," Paysten said. "He spent two years in Q-Cup and got player of the year last year for the Pride, so I like what he provides us."He kicks well, he talks well, and he tackles well, so he ticks those three things off - he's a fair chance of playing every week."
Teenager Jaxon Purdue reassured Payten that there's life after Valentine Holmes, scoring a try in a convincing display in the centres.
John Bateman also showed he would be a handy acquisition, with the 31-year-old second-rower heavily involved.
"I'm really glad we got him," Payten said of the Englishman. "He's earnt the respect of everyone and he's a quality player."
Melbourne captain Harry Grant said the team would put their winless pre-season aside to focus on their round one meeting with the Jason Ryles-coached Parramatta.
Coach Craig Bellamy is looking to keep his remarkable record of never having lost an opening-round match alive, with the stretch currently at 21 straight wins.
Grant said the Storm's faltering attack could be attributed to an unsettled backline missing some key players but conceded their one-on-one defence and discipline needed to improve.
Grant was sin-binned midway through the first half after repeated team infringements, with the Cowboys scoring twice in his absence to take a 18-10 halftime lead.
The scoreline blew out in the second half as Melbourne's defence fell away when they emptied their bench.
"The things to tighten up is probably our discipline. Obviously there's some penalties there that led to me getting sin-binned ... that probably really broke the game open," Grant said."And obviously just our defence. That's probably the big one that's going to be on Craig's list, and top of the list is our missed tackles."
Play was temporarily halted with 15 minutes left when young fullback Hugo Peel was knocked out in a collision with teammate Coby Williamson, with the 19-year-old taken off the field in an ambulance.
Peel was responsive after the match but taken to hospital as a precaution.
The Storm had earlier lost starting fullback Sua Faalago mid-match to a tight hamstring.
First choice No.1 Ryan Papenhuyzen is already in doubt for round one after sitting out the trial with lower leg soreness.
