Cristiano Ronaldo scored a hat trick to secure Portugal's place at the 2014 World Cup at Sweden's expense, while France staged a remarkable comeback against Ukraine to book their place at Brazil.
Leading 1-0 after the first leg in Lisbon, Portugal travelled to Stockholm knowing an away goal against Sweden would put them in a commanding position.
And five minutes into the second half Ronaldo, who scored the winner in Friday's meeting, broke the deadlock as he raced clear and fired home.
On 68 minutes, though, Sweden were given hope when star man Zlatan Ibrahimovic headed in, before the Paris Saint-Germain striker blasted in a low free kick four minutes later.
But the home team's hopes were ended when Ronaldo netted his second of the game with his left foot from a tight angle and then completed his hat trick with another superb finish, as Portugal sealed a 3-2 win on the night.
France fought back from two goals down against Ukraine to seal their place at next year's finals thanks to unlikely two-goal hero Mamadou Sakho.
After suffering a 2-0 loss in the first leg in Kiev, France faced an uphill task in Paris -- and coach Didier Deschamps reacted by making a number of changes, including the selection of Sakho.
And on 22 minutes his faith was rewarded when the Liverpool defender followed up from close range to make it 2-1 on aggregate.
Karim Benzema, selected ahead of Olivier Giroud, then put France 2-0 up on the night, although in controversial circumstances as he was in an offside position.
Ukraine then had Yevhen Khacheridi sent off for a second yellow card, before France completed the turnaround with 18 minutes left thanks to Sakho.
Croatia comfortably won their play off second leg against Iceland 2-0 to qualify for next summer's World Cup.
Mario Mandzukic scored but was then sent off, all within the first half, and Darijo Srna netted a second early in the second period.
Iceland could find no way back and a 2-0 scoreline was enough to see Niko Kovac's side to Brazil.
Greece finished off the job they started in Athens last week as a 1-1 draw with Romania on Tuesday night carried them safely through.
Holding a 3-1 advantage from the opening leg, Fernando Santos' men arrived in Bucharest looking to wrap up the tie and they all but achieved that with a first-half strike from Konstantinos Mitroglou.
A bizarre own goal from Vasileios Torosidis early in the second half pulled Romania level on the night, but there was to be no dramatic comeback as Greece booked their ticket to Brazil 4-2 on aggregate.