Look: Cheerless Costa reacts to Chelsea's winner

On the pitch, a jubilant Chelsea squad celebrated Michy Batshuayi's 94th-minute winner, but in the stands at Atletico Madrid's new Wanda Metropolitano, there was at least one player with Blues blood nonplussed by the ending.

Naturally, the camera wasted little time panning to an executive box where a melancholic Diego Costa sat - fresh off his move from the English capital to its Spanish counterpart - with an expression of sadness partially concealed, but no less evident.

Such is the plight of the mercurial footballer who forced a return to Atleti after a falling out with Chelsea gaffer Antonio Conte, and it was a symbolic moment, as Batshuayi - a player relegated to the bench courtesy of Costa's exploits - snatched a victory from the jaws of a stalemate.

With Atleti hampered by a transfer ban that forbids the club from registering new players, Costa will have plenty of opportunities between now and January to observe from afar, including a Stamford Bridge reunion for a Dec. 5 return fixture.