At one stage, the Bees were 4-1 ahead on Sunday, before two late goals offered United some scoreline respectability.
On the significance of the victory, Frank beamed: "I'm very happy with a very good performance, especially until we scored the fourth.
"After we scored the 4-1 goal, it was close to being a complete performance; dominating, being on top of the game throughout until that moment, scoring four great goals and giving basically nothing away.
"Of course, we're a bit annoyed with the last two goals but it's the Premier League, it's a very good team with very good players.
"Having three players on 10 or more and being the only team to have that in the division is incredible. It was two top goals from Kevin Schade today; two great crosses and two great finishes."
"We want Europe"
Indeed, Kevin Schade also spoke in the aftermath and the Germany was delighted with his two-goal performance.
He continued: "It was two good goals and something we work on in training.
"It was a good chip from (Christian) Nørgaard and from a position like this, I think I can jump very high in there. The second goal was a lovely cross from Bryan (Mbeumo) and a bit lucky because I think it got deflected."
Schade added, "We want to play in Europe.
"We have to win every game now, but it's a positive pressure to have something you can keep playing for."