The Blues suffered their first league defeat of the campaign in London, with Gabriel Jesus's deflected effort proving to be the difference between the two sides.
Azpilicueta has conceded that his side were far from their best in the league encounter, but the Spaniard is already looking ahead to Chelsea's next match, which comes against Juventus in the Champions League on Wednesday night.
"We're disappointed with the result. It was not our best performance. Especially in the first half it was hard to get out. We didn't create chances and lost the ball too easily. After the goal we had a good reaction, but it was not enough to get something from the game," Azpilicueta told BBC Sport.
"They were at their best level. We couldn't keep the ball as we like to do. We made so many mistakes, ones that we normally don't make. We tried to stay in the game. We lost the game after a short corner, which is disappointing.
"We are two great teams with great players and great ambition. Every game is different and every competition is different. We lost our chance to get three important points. Now we have to analyse what we didn't do that well and move on to the next game. We didn't lose the league today. If we'd have won we wouldn't have won the league today either."
Chelsea will be looking to return to winning ways in the Premier League when they welcome Southampton to Stamford Bridge next weekend.