The Belgians were 2-0 down after 24 minutes on Thursday but fought back to draw 2-2 after Italy had Lorenzo Pellegrini sent off near the end of the first half, following a VAR review.
"We really struggled and the red card helped us enormously," Tedesco said.
Italy scored in the first minute as Andrea Cambiaso bundled in a rebound before striker Mateo Retegui made it 2-0 after 24 minutes.
"We know we can do better, but that quick goal against threw all our plans into disarray.
"In possession we stuck to the plan, but without the ball we were too high. The Italians always had a surplus in midfield. So our pressing did not work," the Belgian coach said.
But once they had a numerical advantage, Belgium worked their way back into the contest.
"It's often even harder to score against 10 Italians. They know how to defend. From the moment they dropped back - which happened after the red card - it was harder, but we changed the tactics and it worked,” he said.
One of the switches was to move Jeremy Doku back to his usual position on the left wing where he helped stretch the home defence as Belgium scored through Maxim de Cuyper and Leandro Trossard.
Doku had started the match on the right side.
“At Manchester City he played on the right in their last few games. He usually ends up against two opponents marking him which was the reason why we wanted him there.
“It was not because of Doku's position that we conceded those goals. It was because we played too compactly. Admittedly, things went better after the switch to the left,” said Tedesco.
“But of course we can always improve. And that’s our goal. We’ll try to bring something against France, even though we only have one training session.”
Belgium next take on France in Brussels on Monday, having lost 2-0 in them in Lyon last month.
In Nations League A Group 2, Italy lead the standing on seven points, one ahead of France, who beat Israel 4-1 on Thursday, with Belgium third on four.