Atletico Madrid coach Diego Simeone paid tribute to Leicester City's dogged persistence as the Spaniards saw off the English champions 2-1 on aggregate to reach the Champions League semi-finals for a third time in four seasons.

Last season's runners-up looked set for a calm night when Saul Niguez's pin-point header put them two goals ahead on aggregate before halftime to cool the atmosphere in the King Power Stadium.

Yet a double change from Craig Shakespeare at the start of the second half transformed the game, leading Jamie Vardy to level for the English champions and forcing Atletico to defend with their backs against the wall and see out the 1-1 draw which took them through.

"I feel emotion, pride and hope after such a tough game against a team which gave us so much pleasure to compete against, a team that did not throw in the towel and kept us at arms' length," said Simeone.

"After a game like that it's easy to forget we are in the semi-finals. It was the night of pure football we had envisaged, with a marvellous atmosphere against a team that fought until the end. It was a passionate game with chances for both sides, and these are the games that people love to see."

The Argentine coach has transformed Atletico from sleeping giants to one of Europe's most feared teams in his five years in charge and he said he had fulfilled his initial aim when he took the reins of an ailing club in 2012.

"When I came here five years ago my only hope was to make Atletico a competitive team again and bother every team that we faced, and I think we are competing," said Simeone, who had to rejig his defence after losing Juanfran and Filipe Luis to injury in the second half.

"Shakespeare's changes were fantastic and after their goal they attacked us much more. It took a while to reset the defence but when we did it we managed to cope better with the danger they created," he added.

"The team did what we needed to do to go through. As a coach it is difficult for me to keep praising the efforts of our team because they are magnificent."