Spurs fought back from being 1-0 down at home to lead 2-1 before Matthijs de Ligt found an equaliser for United on 96 minutes.
Afterwards, Frank reflected: "I know we conceded two goals but to concede five shots at goal you would probably take before a game. That's not to say the two shots they have on target, weren't two situations we could have done better.
"We're searching to find the right balance up front. I think when we look at the game back. There were positive bits going forward. We created one of the biggest chances for Richarlison from Brennan's (Johnson) cross early on. He scored before Bryan (Mbeumo) and maybe it opens up the game a little bit more.
"But the best thing about the game was our second-half, where we stuck to the gameplan, stuck to our game and kept believing.
"Which is huge, given our form at home and the Chelsea game, I won't hide from that. Instead, we stuck to our game and didn't get distracted and didn't do things we shouldn't do.
"Then we scored a brilliant goal, we got a second. But then we're disappointed to concede and not to win with 11 against ten.
"But that's football. How often do you see such things? The positive is the players' response and how they kept going."
Frank also said, "Look, I think it was two pretty even teams playing eachother. They want to defend well, as do we, so it can be very difficult to create good chances.
"As I said, we conceded five shots to them. On paper, that's an unbelievable defensive performance. So overall, it was a positive performance in my view."