After a series of surprise first leg results on Saturday, four of the five favourites came through with varying degrees of safety in the second legs as the Dutch led the way thanks to a 6-0 demolition of Scotland in Amsterdam for a 6-1 aggregate win.
Spain put their nerves to one side after an unimpressive 2-1 victory over Norway on Saturday to win 3-0 in Oslo for a 5-1 aggregate success.
Russia, held to a goalless draw by Wales in Moscow in the first leg, won 1-0 in Cardiff to take their place in Portugal, while Croatia, also held to a draw on Saturday, beat Slovenia 1-0 away in the second leg to go through 2-1 on aggregate.
But the biggest shock came in Istanbul where Latvia produced a major upset by knocking out World Cup semi-finalists Turkey to reach the finals of a major tournament for the first time in their short soccer history.
Latvia fought back from 2-0 down to force a 2-2 draw in the last 24 minutes and win the tie 3-2 on aggregate after their shock 1-0 home win in Riga in the first leg.
Although they played as an independent nation until 1940, Latvia have only been playing internationals again since 1991 and the match is certain to mark a turning point for sport in the small Baltic country of just 2.3 million people.
Latvian Football Federation president Guntis Indriksons said: "This is the greatest achievement in Latvian football history, and the result of years of hard work.
"Now it is about time that (Prime Minister) Einars Repse and the rest of the government recognises our efforts," he added, a reference to soccer usually being overshadowed by ice hockey in the country.
Eleven qualifiers were already known before the second legs of the playoffs with the draw for the finals taking place in Lisbon on November 30.
DUTCH DOMINATE
While Latvia triumphed, the dreams of other smaller nations ended with both Scotland and Wales eliminated by traditionally more powerful rivals.
The Netherlands needed just 14 minutes for Wesley Sneijder to wipe out Scotland's first leg advantage and after that they scored with almost embarrassing ease as Ruud Van Nistelrooy grabbed a hat-trick and Andre Ooijer and Frank de Boer added the others in the 6-0
It was Scotland's worst defeat since they lost 9-3 to England in 1961.
Wales, bidding to reach a major finals for the first time since the 1958 World Cup, also failed at the final hurdle losing to Russia in front of 73,000 home fans in Cardiff.
Vadim Yevseyev scored the only goal after 22 minutes and, although Ryan Giggs hit the post just before halftime, the Welsh were left disappointed at the end.
MAJOR SETBACK
It was left to Latvia to live the dream and knock out Turkey whose growing reputation as an emerging soccer nation received a major setback.
A stunning volley from Ilhan Mansiz gave Turkey the lead after 21 minutes and a close-range chip from Hakan Sukur (64) put them 2-1 up on aggregate.
But Jurijs Laizans put Latvia back in front on the away goals rule with a fortuitous strike from a free-kick after 66 minutes before Maris Verpakovskis scored his sixth goal of the competition to ensure Latvia's shock overall win.
Spain also ensured they would be taking part in neighbouring Portugal's party next summer after a convincing win in Oslo with goals from Raul (34), Vicente (49) and Joseba Etxeberria, who scored with a flukey 55th minute header he knew little about.
A weak, short clearance from Norwegian goalie Espen Johnsen went straight to Etxeberria's head and rebounded back over the keeper into the net.
Spain ran out 5-1 aggregate winners but matters were much closer for Croatia who edged Slovenia by the only goal after a second-half strike from the in-form Dado Prso for a 2-1 aggregate win.
Prso scored the decisive goal for Croatia after 61 minutes with a shot from 10 metres after Tomislav Sokota had set him up with a pass from the right.
Just two minutes earlier Croatia's Igor Tudor was sent off after receiving his second yellow card for a foul on Amir Karic.