An excellent cup-tie had dragged on into extra-time, with the two teams having failed to be split following 90 minutes. Michail Antonio had put the Hammers ahead, before a brilliant free-kick from Philippe Coutinho levelled the score. It was to be West Ham's night though, and Ogbonna made sure of it in the 120th minute.
Despite fielding a team mostly containing young, inexperienced players, it was Jürgen Klopp who saw his team start the better, with Liverpool putting huge amounts of pressure on the West Ham goal in the first half.
Young Reds impress early on
One man who certainly wasn't inexperienced, but certainly was out of form, was Christian Benteke, who was getting some joy from corners. With Coutinho back in the team, the Reds had a more natural set-piece taker, and the Belgian got on the end of a couple towards the back post, forcing Darren Randolph into two early saves.
Benteke and Coutinho switched roles later in the half, with the striker turning provider. Slipped in down the left by the Brazilian, Benteke checked back and played the ball back, from which Coutinho saw a shot rattle the post. The ball bounced back out to the edge of the area, where Kevin Stewart struck a shot wide.
West Ham did grow into the game though, and really should have taken the lead with 38 minutes gone. Winning a free-kick around 25-yards-out, Dmitri Payet stepped up and rattled the post, before Simon Mignolet got his hands to a rebound header.
Antonio cracker puts Hammers ahead...
It didn't matter that the Hammers missed their last chance though, as they went ahead just a few minutes later, just short of half time. There was an element of luck about it, as Enner Valencia's cross deflected off Jon Flanagan into Antonio's path. There was nothing lucky about the finish though, with Antonio moving his body brilliantly to volley past Mignolet.
...But Coutinho responds straight away
Liverpool didn't waste their time in responding though, and were level three minutes after the break. Coutinho was the goalscorer, making it 1-1 with a brilliant finish. After Benteke was fouled on the edge of the area, it looked too close to goal for the playmaker to get it up and over the wall, so he tucked a neat finish under the wall, leaving a bemused Randolph picking the ball out of an empty net.
Aaron Cresswell and Benteke both had shots blocked in the following period, but those small chances were overshadowed by two substitutions, as Divock Origi and Daniel Sturridge returned from injury for Liverpool. Taking Joao Teixeira and Coutinho off for that pair, Klopp left Jordon Ibe and Benteke on, making for a very attacking Reds team.
However, a number of West Ham injuries slowed the pace of the game, with Joey O'Brien, Winston Reid and Cheikhou Kouyate all forced off.
The chances did eventually come back though, with Benteke forcing Randolph into a save with a well struck free-kick. Up at the other end, Valencia had half a chance from a cross, but headed high over the bar. Mark Noble was next to go close, almost looking to decide the game with five minutes remaining as he volleyed towards goal, only for Mignolet to catch well.
With the game drifting into extra time, the injury bug bit again. It was a white shirt down this time, as Kevin Stewart went down under the force of Pedro Obiang. Whilst it did look extremely nasty as he went down, the midfielder managed to get back up and run it off.
Eight minutes of stoppage time were announced, and Liverpool went close again. Taking a quick free kick after Origi had been fouled, the ball made it's way out to Ibe on the edge, but Randolph was once again equal to the shot.
Extra-time brings about chances
Into extra-time the game went, and more big chances followed. Noble again was driving forward for West Ham, forcing Mignolet into a strong save with a long range effort. Benteke was shooting again at the other end, the ball dropping for him on the volley, which he hit wide.
Things got even worse for the Belgian a minute later, when Sturridge put him through on goal with a pass. Bearing down on Randolph, Benteke just had the 'keeper to beat, but saw his shot saved. Unsurprisingly, another chance came and went for him, Origi doing well to put a cross in for the striker, who headed over.
The two teams changed ends after 15 minutes, and it was Liverpool who kept pouring forward. Sturridge and Origi took turns to shoot, both striking narrowly wide with difficult looking efforts.
Stoppage time, in extra-time for West Ham
Having been forced into using all their substitutions early due to injuries, West Ham, and their tired legs, went route one - earning a free-kick in stoppage time at the end of the game. With Payet swinging the ball in, Angelo Ogbonna peeled off at the back post, sending a brilliant header back across goal to beat Mignolet.
It was a superb goal, to end a cracking cup tie, one that Liverpool really didn't deserve to lose. However, goals win you games, and Klopp's men didn't take their chances.