Tottenham’s Premier League hot streak came to an abrupt end at Elland Road thanks to Noah Okafor’s 79th minutes winner.
De Zerbi’s side missed the chance to potentially move into the top six, at least temporarily, and are now sat in 11th with 12 points from their 10 games.
Speaking to TNT Sports after the game, De Zerbi didn’t hold back on his assessment of his side’s performance.
“We deserved to lose the game in the second half and didn't play like we can. It's a journey for us, because we can learn from this game,” he said.
“I am sorry for the performance in the second half - we didn't play like a top team. We didn't have the right character and physicality in the second half.”
Leeds defender Jayden Bogle was perhaps lucky to avoid a red card for a rash challenge on Mathys Tel, forcing the Tottenham ace off with an injury.
De Zerbi responded to the controversy, saying: “No. I have big confidence in the referee. Nothing changes if he goes to the monitor.
“If they didn't take the right decision I don't know. We have to keep the eyes on the performance where can improve.”