By Emma Sanders

Diego Costa was on hand to score Chelsea’s first goal after 40 minutes during their clash against Middlesbrough at the Riverside Stadium on Sunday evening – and fans reacted with delight on Twitter.

The 28-year-old has been in sensational form so far this season and netted his 10th goal of the Premier League campaign as Chelsea took the lead in a game they eventually won 1-0 to overtake Liverpool at the top of the table.

Costa struggled to make his mark on the league last season as Chelsea had to fight their way out of the relegation zone in the early months of the campaign.

However, he has returned to top form this season and currently leads the Premier League’s top goal-scorer list, with two goals and three assists more than Sergio Aguero in second place.

The striker has played in every league game under Antonio Conte this season and has scored in the last three successive games for Chelsea.

He averaged a goal every 107 minutes prior to kick-off and has only failed to score in five matches in all competitions for the Blues throughout the 2016-17 campaign.

Chelsea have lost just one game in which Costa has scored – their 2-1 defeat against Liverpool in September – so fans were confident their team would grind out another three points following his first half goal against Middlesbrough.

Here is a selection of the messages on Twitter:

In other Chelsea news, Paul Merson gives his verdict on these two Stamford Bridge stars.