Croatia were beaten in the opening game of the tournament by hosts Brazil, with Saints defender Lovren giving away a penalty in a 3-1 defeat.
However, they bounced back last night with a 4-0 victory to move to within a point of joint-leaders Brazil and Mexico, and send the African nation out of the tournament.
Lovren started the game at the Arena Amazônia in Manaus, with Croatia going ahead after only 11 minutes through Ivica Olić.
They were given a further boost five minutes before the break when former Arsenal midfielder Alex Song was shown a red card.
The Croatians duly turned the screw after the break, with Ivan Perišić making it 2-0 after 48 minutes.
Mario Mandžukić added a third just after the hour mark, before doubling his account on 73 minutes to round off the win.
Group A reaches its conclusion next Monday, 23rd June, with two of the top three going through to the last 16.
Croatia face Mexico at the Arena Pernambuco in Recife, while hosts Brazil face already-out Cameroon in Brasília’s Estádio Nacional. Both games kick off at 9pm BST.