Marc Skinner's Reds scored three times in the first half alone at the Broadfield Stadium in Crawley, ultimately blowing the Seagulls away following two Women's Super League games without a win.
"It was very nice to be on the pitch today because we've had a little bit of a tough season this year," Naalsund explained.
"It feels like with the combinations, we're playing very good [football] and scoring great goals. So it's nice to see that we've got it in us, it's just been a little bit rough."
A jubilant Millie Turner, scorer of United's first goal after eight minutes, echoed those thoughts, saying: "[It was an] unbelievable game from us.