The Warriors controlled the majority of the game but were unable to put it out of the Panthers' reach and were made to pay.
"We did so well – we got enough points, we got to the right part of the field, it was just a crucial moment that we lost it for ourselves," Tuivasa-Sheck told the Radio Sport Breakfast.
However, with 10 games left in the season it's imperative for the Warriors to string together some results, starting with this weekend's trip to McDonald Jones Stadium for a clash with the Newcastle Knights.
With the Knights missing halfback Mitchell Pearce and prop Daniel Saifiti (State of Origin) and fullback Kalyn Ponga (injury), the Warriors will look to take advantage of a weakened Newcastle side to try and keep even a glimmer of hope in their season.
"We've got to get these points," Tuivasa-Sheck said. "We've got to get a run going."
The Warriors go into a period on their schedule where they will be away from Mt Smart Stadium for the best part of a month, with their next four games being away to Newcastle and the Brisbane Broncos, in Wellington against the Cronulla Sharks, and away to the Parramatta Eels.
It's not necessarily the worst thing for the Warriors, who have not won at Mt Smart Stadium in their past five matches at the venue, winning just two of seven this season at what used to be their fortress.
On the whole, they've performed better this season when on the road, with three wins and some agonisingly close defeats to some of the league's top teams.
"On the road, we need to start making it happen," Tuivasa-Sheck said.