If only

Spain reign the world but it could have been different if only the referee had awarded the Netherlands a corner or free-kick moments before the Spanish goal, though the Dutch could have been reduced to 9 men and virtually out of the game by half time. A single goal or the lack of it due to a refereeing decision or missed chance changed the fate of many teams in the World Cup.
In the last minute of the very first match of the tournament Mphela hit the outside of the Mexican post for South Africa who finished below Mexico and were eliminated on goal difference but could have progressed from group A to the next round had the ball gone in off the post and turned their first draw into a win.
In group B Nigeria finished bottom but could have made it to the next stage instead of South Korea had Yakubu not missed an open goal in their 2-2 draw against the Koreans.
England were several times a goal away from winning group C. Even without the winning goal against the USA or Algeria, or the 2nd elusive goal in their victory over Slovenia, England would have won their group ahead of the Slovenians had the Americans not scored deep into stoppage time against Algeria. Winning their group would have given them arguably an easier path to the final.
Ghana scored a penalty in their win over Serbia and draw against Australia, but failure to convert either spot kick could have seen their opponents through in their place. Having scored both penalties the Ghanaians were poised to win group D when a wondershot by Özil put Germany in poll position changing the shape of things to come.
Group E may have been the most straightforward group but 4 of the 6 matches were decided by one goal.
Italy lost their title and finished bottom of group F but could have made it to the next round instead of Slovakia had late effort against the Slovaks not been disallowed. On the other hand had the Italians failed to convert their equalising penalty against New Zealand, the Kiwis could have made history by moving into the last 16.
Two goalless draws for Portugal against the Ivory Coast and Brazil could have gone either way changing the outcome of group G. In particular the first match in which a victory for the Ivoirians could have seen them through instead of Portugal whereas a win for the Portuguese could have seen them top the group earning them a meeting with Chile instead of Spain whom the Brazilians would have faced in the next round.
The position of the top teams in group H was decided by goal difference, keeping Spain and Brazil apart in the next round. Switzerland were 15 minutes away from holding Chile which could have seem them through instead of the South Americans.
In the round of 16 only Brazil eased through without incident. Germany may have hammered England 4-1, but the English were cruelly denied an equaliser by an obvious refereeing error after fighting back from 2 down and were consequently taken apart in the 2nd half. Mexico also felt aggrieved when they saw the officials award Argentina an offside goal to break the deadlock. Ghana disposed of the USA in extra time and Paraguay needed a penalty shootout to eliminate Japan while in the 3 remaining matches there was only one goal between the winning and losing sides with Uruguay, the Netherlands and Spain getting the better of South Korea, Slovakia and Portugal respectively.
In the quarter-finals Germany may have been clear winners over Argentina, but in a game of missed and retaken penalties a single goal put Spain through against Paraguay and a Brazilian dismissal allowed the Dutch to get the better of their illustrious rivals while Ghana missed a penalty with the last kick of extra time allowing Uruguay through after a shootout.
Both semi-final losers needed only one goal to take their match to extra time and possibly the lottery of a penalty shootout, as was the case in the third-place match play-off and final. With so many teams fantasizing over what may have been, it is only Spain who will wish to relive their golden dream turning to reality.