The match was the Bluebirds' first since Sala's plane disappeared when travelling back to Cardiff from Nantes last Monday after he said his farewells to his former colleagues having completed a move to the Premier League side the weekend before.
The search was called off on Thursday, before a private operation was started three days later when Sala's family reached a €300,000 crowdfunding target.
And Warnock felt the team did Sala proud on the pitch.
"We talked about Emiliano before the game and I thought it was appropriate that we gave a good account of ourselves against a good side and I thought we could've won the game," Warnock told BBC Sport.
"What a performance, if Arsenal had our chances they would've beaten us by four. Nineteen shots at the Emirates, it's definitely our best performance of the season."
Pierre-Emerick Aubameyang and Alexandre Lacazette were on target for Arsenal, before Nathaniel Mendez-Laing scored a consolation in second-half injury time for Cardiff.