Monaco coach Leonardo Jardim said Arsenal “lacked respect” after Arsene Wenger's decision not to shake hands with him or congratulate his side after their 3-1 first-leg victory.
The principality side were on the brink of elimination from the Champions League after Arsenal overwhelmed them in their last-16, second-leg tie at the Stade Louis II to win 2-0, but Monaco progressed on away goals.
After the game Jardim hit out at Arsenal, claiming Wenger did not acknoweldge Monaco's achievement.
"I wanted to shake Wenger's hand [after the first leg] but he didn't wait so, even though Monaco did everything for Arsenal, I decided not to thank him," Jardim said.
"Arsenal didn't show the respect they should have after the first leg."
He added that the teams remaining in the competition had not learned the lesson that Monaco should not be underestimated.
"I am sure that all the teams will want to draw Monaco in the quarter-finals," he said in his post-match press conference.
"The qualification is totally deserved," Jardim added. "Arsenal benefited from two errors to score."
The Gunners were the better team, though, scoring through Olivier Giroud and Aaron Ramsey, before Monaco keeper Danijel Subasic made several saves as the hosts survived the onslaught.
Arsenal managed seven attempts on target while Monaco's only shot was off target, but the Ligue 1 team had not conceded three goals at home in more than three years.
"It was the game we expected. Very intense," said Jardim.