"This is our best performance of the season," Frank said. "The mentality to stay in the game, keep going, and come back - that really impressed me."
Goals from Richarlison and a Jan Paul van Hecke own goal completed the comeback, with Spurs dominating much of the match. They registered 45 touches in Brighton's box and 11 shots, though only three were on target.
"We were completely dominating," Frank added. "If there should have been a winner, it should have been us."
The comeback ended a run of 15 consecutive away league losses when trailing by two or more goals - a statistic that Frank sees as proof of growing belief and resilience within the squad.
"This group came here last year and lost after leading. Now, we're 2-0 down and get back to 2-2 - that says everything about where we're heading," he went on.
Frank also pointed to standout individual performances, singling out Mohammed Kudus for his influence on the right flank.
"Kudus was probably our man of the match. He was so dangerous - he created the own goal with his run. That kind of impact lifts the whole team.
"There are still areas to improve - finishing, decision-making - but with this structure, fitness, and mentality, we're on the right track," concluded Frank.