​Chelsea manager Antonio Conte was unhappy with his side's result against Swansea on Sunday, citing a refereeing mistake as a major contributing factor to his side dropping two points.

The Blues had taken the lead before the 20 minute mark, with Diego Costa curling home from Oscar's lay off.

Swansea then went in front the lead thanks to two quick strikes from Gylfi Sigurdsson and Leroy Fer, before Costa acrobatically equalized, and Conte was philosophical regarding the incident involving Fer and Chelsea defender Gary Cahill.

Swansea City v Chelsea - Premier League

"People looking at the second goal can see that the referee made a mistake, but this can happen. I've not spoken to the referee. It's a big mistake," the former Juventus and Italy boss ​told BBC Sport.

"It's very difficult to talk about the game because we lost two points. We were leading 1-0 and created a lot of chances to score another goal. We are disappointed because the performance was very good in terms of our intensity and because we played good football."

The result means Chelsea's winning start to the season has ended, although the club remain unbeaten, and have moved above Manchester United into second place in the Premier League table.

Diego Costa was at the heart of the action again on Sunday, frequently being involved in altercations with Swansea centre-backs Federico Hernandez and Jordi Amat, and Conte defended the Spaniard, insisting that he needs protection from referees.

"Every game the press ask me about the patience of Costa, his behaviour. His behaviour was fantastic. Today he took a lot of kicks," ​Conte continued.

"I think the defenders know him and sometimes they try to provoke him. It's football and it's normal in this situation. They try to provoke but it's football, not only in England but in general in the world. The referee must see it and permit Diego Costa to play his football."

Chelsea continue their Premier League title bid on Friday night, with a home fixture against Liverpool.