The Blues manager caused controversy last summer when he informed the Spanish striker that he was no longer wanted at Stamford Bridge.
That led to more fallout between the pair, with Costa frozen out in London for half a season before finally joining Atletico Madrid in January.
At Chelsea, Costa scored 59 goals in 120 appearances and helped the club to three major trophies, including two La Liga titles.
But several fallouts led Conte to get rid of Costa – and based on his fine showing against Portugal tonight, that’s something some Chelsea fans are still salty about.
He bullied the Spain defence in a 77-minute runout and scored two great goals in the pulsating 3-3 draw.
This was the reaction of some Chelsea fans to his performance:
Little reminder: Antonio Conte binned Diego Costa with a text message and got Alvaro Morata to replace him.
— CarefreeDaily. 🚬 (@CarefreeDailyFC) June 15, 2018
Costa making Conte look a fool
— Soldier↪ (@PatohShanqueels) June 15, 2018
Diego Costa, yes….Diego Costa is the striker Antonio Conte got rid off just to replaced him with Alvaro Morata 😹😹😹
— Elikem Strokz 🇬🇭 (@IamStrokz) June 15, 2018
Conte, can you see the Diego Costa you swapped for Morata? Oponu
— Series Abíọdún࿐ (@Engr_Series) June 15, 2018
I miss Diego Costa… Dunno what Conte was smoking
— Imoh Umoren (@ImohUmoren) June 15, 2018
Costa makes me dislike Conte the more
— Mr. Jack Robinson (@jackdre02) June 15, 2018
Diego Costa is a beast. Fuck Conte
— iBhubesi (@mabasotf) June 15, 2018
Costa took on the entire Portugal defence and came out on top. Conte doesn’t rate him tho.
— francis. (@stayne_) June 15, 2018
Fuck you Conte for calling Costa to leave
— DADDY THE FATHER (@SemilooreAkoni) June 15, 2018
This is the COSTA that Conte dismissed from the team. Worst decision ever made by a football manager.
— Babs 🦅🇳🇬 (@BabatundeCASH) June 15, 2018
I still don't know why Conte sold Diego Costa😥😥
— Bisola Oyewole (@_Abisolah__) June 15, 2018
Conte slyly has to hold a L for selling Costa
— Uncle Ed (@UncleEd419) June 15, 2018
Conte sold Costa for Morata, no wonder we went down. 😂
— Biodun (@___biodun) June 15, 2018
As a Chelsea fan I hope Abramovich & Conte watched that beautiful Diego Costa goal and lose sleep tonight about getting rid of that absolute beast #PORESP
— Sammy Leighton Clay (@SammyLClay) June 15, 2018
Diego Costa goal is a reminder that Conte is very stupid
— Tayọ̀ Blesser (@createdbyTayo) June 15, 2018
That goal by costa is why Conte needs to get sacked. How can you sell a player like him?!
— TaqsLife (@TaqHussain) June 15, 2018
You get the point.
Unfortunately for Costa and Spain, Portugal recovered from 3-2 down to equalise with a beautiful Cristiano Ronaldo free-kick and that was enough to level it at 3-3.