Diego Costa Chelsea Liverpool
Diego Costa fires home the winner for Chelsea against Liverpool in their English Premier League gameReuters

Diego Costa – love him, hate him, try to ignore him - one thing that cannot be changed is the man scores goals, and plenty of them, and quite important ones as well.

With the Liverpool vs Chelsea English Premier League game at Anfield perfectly poised at 1-1 with a little over 20 minutes remaining in the game, in stepped that awesome striker of Chelsea to be at the right place at the right time and hammer the ball into the back of the net.

That Costa second half goal gave Chelsea a 2-1 victory over Liverpool, who threw away at least a point, maybe even three, after scoring the opening goal.

The first goal came via Emre Can and it looked like the fillip and tonic needed for Liverpool to go on and take the game to the league leaders, but Gary Cahill equalised almost immediately from a corner, before Costa thrust that dagger in right where it hurts with the winner.

It is a definitely-insurmountable 15-point lead for Chelsea from Liverpool with this victory, as the Blues also increased their lead at the top to seven points, while keeping those hopes of emulating the Arsenal "Invincibles" very much alive.

All the pressure was on Liverpool to get a positive result out of this game and also justify Brendan Rodgers' decision to rest his main men for that Champions League clash at the Bernabeu against Real Madrid in midweek.

Emre Can, preferred in the middle of the park to Joe Allen, was the first one to take the game to Chelsea, though firing a shot from distance which took a nick off John Terry and could have easily looped into the net.

However, the midfielder would not be denied a second time, as another shot from distance took another deflection off a Chelsea defender, this time Terry's central defensive partner Cahill, to outfox Thibaut Courtois and make that net bulge.

It was the kind of start that Rodgers would have asked for in the meeting before the match, but the manager would have also stressed on the importance of keeping that lead for as long as possible – because after all, the longer Liverpool stayed in the lead, the more Chelsea would have to come forward, which would then allow the home team to beat the away side at their own game on the counter-attack.

But Chelsea are a different beast this season, and there was absolutely no panic after conceding that early goal, just a flick of the switch and a movement into top attacking gear. Chelsea put Liverpool under pressure for a while after going a goal down, and five minutes from that opening strike they were level.

Cahill was the man to take the plaudits, forcing the ball over the line despite the best efforts of Simon Mignolet. It was another setpiece that troubled Liverpool with Costa climbing high and winning the first header before John Terry headed one of his own to force a good save from Mignolet.

However, there was Cahill to pick up the rebound and fire a shot at Mignolet, who despite saving the ball could not prevent it from going over the line as he himself fell over – the brilliance of goalline technology came to the fore here as Anthony Taylor, after initially waving play on, gave the goal as it popped up on his futuristic wristwatch.

Liverpool for all their possession just did not have that cutting edge in the final third, something they have lacked all season in the absence of Luis Suarez and Daniel Sturridge. Mario Balotelli certainly looked up for the game, but service to him was pretty poor, with Coutinho despite a wonderful run which nearly ended up in a goal, unable to ping in those through balls, while Raheem Sterling was nullified by Branislav Ivanovic.

Chelsea were more dangerous going forward, always looking capable of opening up the Liverpool defence, with Costa as is his wont, making himself a right old pest.

There was plenty of argy bargy between Costa and Martin Skrtel, and the Chelsea man will go back to London thinking he has won the battle, thanks to that goal.

However, it wasn't Costa who had the chances to make it 2-1 in the first half as Hazard saw two glorious opportunities blocked brilliantly by Glen Johnson. The second one with plenty of room just on the edge of the box was the best and looked destined for the back of the net only for Johnson to throw his body in front and make an outstanding block.

Chelsea looked stronger as the second half started with Jose Mourinho bringing on Willian for Ramires early in the second half.

Costa threatened here and there as he continued to frustrate the Liverpool defence but it took Chelsea until the 67th minute to take the lead for the first time in the game. Cesar Azpilicueta sprang forward on the left before leaving Philippe Coutinho for dead – the ball might have gone into touch just before that – and playing in a cross which was parried by Mignolet.

Unfortunately for Liverpool that parry via a slight deflection from Alberto Moreno fell to Costa, who did what he does best – thump the ball into the back of the net.

Liverpool did their best to fight back in the game and at least find that equaliser with Rodgers throwing in Fabio Borini and Rickie Lambert, but the goal would not come despite the best efforts of Steven Gerrard, the man most keen on some retribution after the infamous slip-up last season - the skipper left fuming and disappointed in the end as a late penalty appeal was turned down.