Croatia's players celebrate after Luka Modric converted a penalty against Nigeria on Saturday night. Photo: Petr David Josek/AP

KALININGRAD, Russia – An own goal and a penalty from captain Luka Modric helped Croatia down Nigeria 2-0 on Saturday to take early control of World Cup Group D and give their star-studded squad an ideal start to the campaign in Russia.

Oghenekaro Etebo was helpless in deflecting the ball into his own net in the 32nd minute, and a second half spot-kick from Real Madrid star Modric sealed the points.

Nigeria rarely looked capable of threatening an equaliser, and must improve considerably to have any chance of reaching the knockout phase.

Argentina were held to a 1-1 draw with Iceland earlier in the group. Croatia next meet the two-time champions Argentina on Thursday, while Nigeria take on Iceland on Friday.

Croatia finished a brilliant third in their debut World Cup at France 98, but have since failed to progress past the group stage. That is expected to change this time as a golden generation, Modric at its heart, tries once more to click on the biggest stage.

Ivan Perisic fired over from outside the box, but the Nigerian defence could generally keep the opposing forwards at bay. That changed with a stroke of blind luck when Mario Mandzukic threw himself at a flicked-on corner and headed the ball off Etebo to deflect beyond keeper Francis Uzoho.

Andrej Kramaric looped a header on to the roof of the net, and halftime arrived with neither team having officially registered a shot on target.

Nigeria emerged invigorated from the break, and Victor Moses dragged a shot wide of the near post after cutting in from the right. A save was finally made in the 59th minute when Danijel Subasic easily held a weak header from Odion Ighalo.

But when Mandzukic was grappled by William Ekong at a set piece, Modric coolly sent Uzoho the wrong way from the spot to seal the tie with 19 minutes remaining.

Substitute Mateo Kovacic could even have made it three in injury time, but sent a weak shot straight at Uzoho.