Arsenal midfielder Jack Wilshere feels the Gunners played a good game at Stamford Bridge but was not enough.
Chelsea controlled the game and took full advantage when chances presented themselves, opening a five-point gap at the top of the table and with Arsenal already nine points behind.
"It was frustrating and we're disappointed," Wilshere told Arsenal Player.
"It was obviously better than last year's result but at the end of the day we still have the same outcome: no points and a disappointed team.
"We felt that we did alright. In the first 20 to 25 minutes we wanted to come out and keep a clean sheet.
"In the big games in the past we have lost it in the first 20 minutes so we wanted to keep it tight and I thought we did that.
"Then unfortunately there was a bit of magic from Eden Hazard and they got a penalty - you can't plan for that.
"I thought we did alright in the second half - we had periods of possession when it felt like we were on top and we had a few half chances, but we didn't create a clear-cut opportunity - maybe on another day we would score one of those half chances and create a few more.
"We didn't really see Costa or Fabregas all game and then all of a sudden he gets an opportunity, plays a 50-yard ball to Costa and it's a goal.
"That is the difference at this level, we are playing against teams who, when you are on top, you have to make it count or they will punish you. That is what they did."