* Defending champions crash out
* Spanish reign ends on same day King Juan Carlos abdicates
* Chile confirm pre-tournament talk of team to watch (Writes through, adds details)
By Mike Collett
RIO DE JANEIRO, June 18 (Reuters) - One of the greatest dynasties in modern football came to a shattering end when champions Spain lost 2-0 to Chile on Wednesday and crashed out of the World Cup with their glory days consigned to the history books.
On the day when Spain's King Juan Carlos signed his abdication papers, the country's footballers were forced off their throne as first-half goals from Eduardo Vargas and Charles Aranguiz earned Chile a stunning victory in front of thousands of their ecstatic fans in a 74,000 crowd at the Maracana.
The South Americans, who attacked the holders from the first whistle, reached the last 16 along with the Netherlands and confirmed the pre-World Cup talk that they could advance deep into the tournament with a disciplined display against a tired-looking Spanish side who go out along with Australia.
The Dutch, who beat Spain 5-1 last Friday, and Chile each have six points and they meet in Sao Paulo on Monday to decide the group winners. Spain face Australia in Curitiba bidding to avoid finishing bottom of Group B.
The Chileans swept into the lead after 20 minutes following a counter-attack on the right which set up Aranguiz to provide the cross for Vargas who danced around keeper Iker Casillas before firing home.
Casillas, who had a poor game against the Dutch, was at fault again for the second goal, punching an Alexis Sanchez free kick straight back to Aranguiz who placed the ball past the keeper with a spinning shot two minutes before halftime.
But he fluffed his kick to howls of derision from the Chilean fans and Spain never looked like winning after that.
"We cannot complain we did not deserve to go out, they were better than us," Spain coach Vicente del Bosque told reporters.
"The team showed character, we pressed forward but we had little luck in front of goal.
"We were certainly inferior to our rivals here at the finals. It is not the moment to think about the future. Little by little we will make the necessary assessments."
Chile midfielder Arturo Vidal, who had a fine match, was unsurprisingly in upbeat mood.
"We showed we are at a very good level," he said.
"We didn't come for a holiday, we came to fight for the championship."
Spain became the third champions in the last four World Cups to be eliminated at the first hurdle and their departure will almost certainly end the long international careers of their greats Xavi, Casillas and Xabi Alonso.
Xavi, for so long the fulcrum of the side who won the 2008 and 2012 European Championships and their first World Cup in South Africa four years ago, did not even make the starting lineup.
His long-term partner Andres Iniesta, tried to do what he has always done best but made little impression against the inspired Chileans.
SHARP AND CONFIDENT
Chile, who had never beaten Spain in 10 previous meetings, looked sharp and confident from the start and even faster and more fluid in the second half.
Playing with the masterful Vidal in the hole behind Alexis Sanchez and Vargas, they controlled the play and he pulled the strings as Chile showed the old masters how it should be done.
With more composure in front of goal following a series of rapid-fire counter-attacks, they could easily have scored more, confirming the suspicion first raised about Spain at the Maracana a year ago when Brazil crushed them 3-0 in the Confederations Cup final.
At the time that seemed a possible dress rehearsal for the World Cup final, but Spain never hinted they could win this match let alone the tournament on a night that belonged to Chile, a former colony of the Spanish crown.
It was an attacking game from beginning to end, with Spain's back four looking to push forward to help create the goals to put Spain's World Cup campaign back on track.
But when the chances did come, they were all wasted or thwarted by Claudio Bravo in the Chilean goal.
(Editing by Ed Osmond)