Kahn Fotuali'i says that over Scarlets is the perfect preparation ahead of facing English side Leicester in Europe.
Ospreys kept their Heineken Cup hopes alive with a and carried that form into their Pro12 clash with Scarlets.
Pro12 games against Newport Gwent Dragons and Zebre await before the 12 January home clash with Leicester.
"It's very important because it builds a bit of confidence," Fotuali'i said.
"We've just got to keep raising the bar and enjoying ourselves, and when you enjoy it you tend to play a little better.
"Everybody who takes the field... we're all on the same page, we understand the game plan and that's crucial as a unit."
The Ospreys scrum was key in the Boxing Day humbling of Scarlets, who had two men sent off and three others sin-binned as the visitors' discipline disintegrated under pressure.
"[We had] better desire, better want is what it comes down to in these derby games," added scrum-half Fotuali'i, whose man-of-the-match performance against Scarlets included a try and a drop-goal.
"All the boys in there know what to do and what it's about.
"Full credit to our forwards who gave us a good platform to play off and the backs just sort of took it from there.
"We've got some really exciting backs, some young talent out there as well, but when the forwards give us some good ball we're able to produce something like [against Scarlets]."