The Africans announced their arrival with a comprehensive victory on a night that the Spanish struggled to shine despite a big win and Saudi Arabia stunned CroatiaGroup C
Costa Rica 1-4 Spain
Tournament favourites Spain opened their World Cup campaign with a 4-1 victory over a lively Costa Rica side in Manizales despite producing a laboured performance.
Julen Lopetegui's young starlets began brightly and threatened to run riot after Rodrigo Moreno gave them the lead in the 14th minute. Rodrigo got his second soon after the break when he punished some poor defending, but the Central Americans battled back well and halved the deficit when John Ruiz struck with 25 minutes remaining.
Spain were not to be denied, however, and a 85th-minute strike from Koke, followed by an Isco spot kick deep into stoppage time, secured them the points.
Australia 1-1 Ecuador
In the night's other Group C game Australia salvaged a precious point thanks to a spectacular last-gasp free-kick against Ecuador.
The Socceroos had trailed for most of the game following Juan Govea’s 24th-minute close-range strike, but Thomas Oar broke Ecuadorian hearts as he rifled in a free-kick on the stroke of full-time to tie the game at 1-1.
The final result was probably a fair reflection of a game that entertained without really catching fire, but it will be the Australians who will be the happier of the two sides.
Nigeria 5-0 Guatemala
Nigeria crushed minnows Guatemala 5-0 in a one-sided game in Armenia, putting them firmly in control at the top of Group D.
The impressive Africans had far too much quality for their inexperienced Central American opponents and the assured and stylish performance will have delighted coach John Obuh.
A brace from Edafe Egbedi gave Nigeria a two-goal cushion going into the break and second-half goals from Abdul Ajagun, Olarenwaju Kayode and Ahmed Musa completed the rout over the shell-shocked Guatemalans.
Croatia 0-2 Saudi Arabia
Saudi Arabia produced the first real shock of the tournament as they defeated Croatia 2-0 in the group’s other game of the evening.
Despite dominating possession, Croatia went behind in the 54th minute as Yasir Alfhami’s long-range effort took a wicked deflection to leave the goalkeeper stranded.
The advantage was doubled with 20 minutes to go when substitute Fhad Allmuwallad finished off a glorious counter attack, to put the game beyond Croatia and record a deserved victory for the young Saudis.