Tajikistan coach Petar Segrt said the Asian Cup debutants had "no limits" after reaching the quarter-finals with a dramatic 5-3 penalty shootout win over the United Arab Emirates on Sunday.
Alisher Shukurov buried the final spot-kick in Doha to send the Central Asians -- ranked 106th in the world -- into a showdown with either Jordan or the 2007 champions Iraq.
Tajikistan goalkeeper Rustam Yatimov saved from Caio Canedo with the UAE's second penalty of the shootout.
Tajikistan had looked set for a famous victory when Vakhdat Khanonov scored with a 30th-minute header, only for Khalifa Al-Hammadi to equalise in the 95th minute and send the game into extra-time.
Segrt called his team "the black horses of the tournament" and said "nobody knows how far we can go".
"I have no limits for the players because every game they surprise me again," said the charismatic Croat.
"My next dream is to go to the next round again. I think in Tajikistan tonight, nobody will sleep."
The UAE reached the semi-finals at the last two Asian Cups but Paulo Bento's side bow out to a Tajikistan team ranked more than 40 places lower than them.
Tajikistan drew with China and beat Lebanon in the first round to advance as Group A runners-up.
They will learn who they play in the quarter-finals when Iraq take on Jordan in the last 16 on Monday.
Segrt said the UAE's late equaliser had taken the wind out of his team but "then very fast the players got up".
"This is the character of the players, of the coach, of the country," he said.
"This is the fighting spirit."
- Injury trouble -
The UAE qualified as runners-up in Group C after an up-and-down first round that saw them beat Hong Kong, draw with Palestine and lose to Iran.
They suffered an early blow when midfielder Abdalla Ramadan went down with a knee injury and had to be replaced in the 16th minute.
"He was really important in the minutes that he was on the pitch because it allowed the team to make the build-up in the right way," said Bento.
Tajikistan took the lead when Khanonov climbed above Canedo to connect with a header that UAE goalkeeper Khalid Eisa fumbled over the line.
"I dedicate this goal to my brother who passed away," the defender said after the game.
"He is not with us and can't see my happiness."
Tajikistan had chances to double their lead in the second half and Alisher Dzhalilov was wasteful when he blazed wide with the goal at his mercy after making a lung-busting run to get into the box.
The UAE hit the post in injury time before Hammadi notched a dramatic equaliser, rising to head home Ali Saleh's free kick and send the game into extra time.
Yatimov dived low to his left to save Canedo's spot kick in the shootout to give Tajikistan the crucial advantage.
"Yatimov is the best player for me because he saved his penalty but it's not the first time," said Segrt.
"In the end, my friends, it was also luck."
Australia became the first team to qualify for the last eight when they beat Indonesia 4-0 earlier on Sunday.