Spurs won 1-0 in Hong Kong thanks to Pape Matar Sarr's long-range strike.
Frank admitted afterwards they didn't approach the game as a preseason friendly.
He said, "Yeah that is very pleasing of course. I think we have been very clear that this was not a friendly. It felt like a competitive match, I think you saw it was competitive and if you played in it it was competitive.
"Some of the bits we have been working hard on is the combination of defensive organisation so high pressure, middle, low so there are clear principles and that desire to keep a clean sheet because that gives you a bigger opportunity to win matches.
"An unbelievable goal. Fantastic, well taken. All the credit to Pape. He has impressed me I must admit. He has been really good in the last four weeks."
On the significance of victory over Arsenal, Frank continued: "I think for the team we are building together all the positive results or performances you can get just reinforce the messages we try to get into the players and the team feel that. That desire to defend was good. First half in generally we played very good overall.
"Second half I felt we defended a bit too much. But that was good and the set-pieces I think was a good as well. We defended very well but were also very dangerous."
Praise for Kudus
Frank also had praise for Mohammed Kudus on the night.
He also said, "I think he was really good today Kudus. His hold-up play, the way he takes hold of the ball in tricky situations. His one-vs-one skills, his creating opportunities for the team was top class.
"On top of that I think he's working extremely hard and there was was recovery run from a set piece when he was straining all the way back and he won the ball back. That's how he can help the team so much. He will make a lot of the fans excited with his offensive actions and he will also help the team defensively."