Diego Costa clashes with Iker Casillas: Chelsea forward lucky to avoid red card

The Spain international could have been sent off for the unnecessary challenge

Diego Costa (GETTY IMAGES)

Chelsea striker Diego Costa was fortunate to remain on the pitch after an unnecessary clash with Porto goalkeeper Iker Casillas in the first half of the Champions League group game at Stamford Bridge.

The aggressive forward was back in the starting line-up for the crucial match having found himself on the bench for Chelsea's recent games.

Yet his return might have been marked by a red card had there been a stricter referee than Turk Cüneyt Çakir officiating the match.

Early in the first half, Casillas collected the ball inside his area just before hot-head Costa could get to it. As the Porto goalkeeper looked up to see where he could pass the ball, his Spain team-mate inexplicably tripped him up.

The referee decided to issue Costa with just a yellow card, despite Champions League referees' notorious habit of flashing harsh red cards.

The match was 1-0 at the time.