After an almost flawless qualifying campaign, Iran will find it far tougher at the World Cup.
Iran's route to the round of 16 from Group B could be blocked by defending European champion Portugal and 2010 World Cup winner Spain.
But the Iberian teams have good reason to be wary. Iran was unbeaten in 10 qualifiers and did not concede a single goal in the first nine games. And the strongest backline in Asia was only breached by Syria after Iran's place in Russia was already secure.
Contesting back-to-back World Cups for the first time, Iran will be aiming for a first appearance in the knockout stage in its fifth attempt.
Since the 2014 tournament, when Iran finished with one point, the team has evolved and coach Carlos Queiroz has more options in every position — with more than half of the squad gaining experience at overseas clubs.
Queiroz has publicly reminded the Iranian federation of the need for perfection in the World Cup build-up, reflecting concerns about past preparations. After being the first team from Asia to secure a spot, Iran was the first visiting team to arrive in Russia ahead of the World Cup.
"We have achieved this dream through lots of hard work and sacrifices, which only heightens how honored and privileged we feel to be here," Queiroz said. "We arrive raring to keep this dream going for as long as possible and we look forward to playing our part in making this the best World Cup ever."
Here's a closer look at the Iran team:
Queiroz has now steered three teams through four World Cup qualification campaigns.
The experienced tactician has been in charge of Iran since 2011 and has taken the team to new heights.
On the field, he has produced a disciplined and well-organized team that has an attacking threat. That success means that his regular run-ins with the federation and club coaches in Iran are tolerated. Queiroz's status is enhanced by previous experience coaching Real Madrid and Portugal.
Alireza Beiranvand is likely to get the nod in Russia. At 6-foot-4 (1.95 meters), Beiranvand is physically commanding, a fine shot-stopper and known for his distribution, especially with his long throws.
Beiranvand has been in excellent form for Iranian club Persepolis. One potential issue is that his understudies do not have much international experience.
There are plenty of options in defense.
The back four has been well-marshalled, and younger players including Rouzbeh Cheshmi are now getting a look in. Watch out for the speed of fullbacks Milad Mohammadi and Ramin Rezaeian.
Ehsan Haji Safi, Masoud Shojaei and Ashkan Dejagah bring World Cup experience and scoring ability. Talented players such as Saeid Ezatolahi and Saman Ghoddos offer more energy.
The World Cup could be the stage for Alireza Jahanbakhsh to secure a big-money move from AZ Alkmaar after rising to the top of the Dutch scoring charts.
Sardar Azmoun is already accustomed to the World Cup hosts after spending the last five years playing in Russia, performing impressingly recently at Rostov and being linked with a move to a bigger league after the tournament.
Karim Ansarifard and Mehdi Taremi are also a source of goals.
Iran opens on June 15 against Morocco before taking on Spain on June 20 and Portugal on June 25.
Goalkeepers: Alireza Beiranvand (Persepolis), Rashid Mazaheri (Zob Ahan), Amir Abedzadeh (Maritimo)
Defenders: Ehsan Haji Safi (Olympiakos), Roozbeh Cheshmi (Esteghlal), Milad Mohammadi (Akhmat Grozny), Morteza Pouraliganji (Al Saad), Mohammad Reza Khanzadeh (Padideh), Pejman Montazeri (Esteghlal), Seyed Majid Hosseini (Esteghlal), Ramin Rezaeian (KV Oostende).
Midfielders: Mehdi Torabi (Saipa), Saeid Ezatolahi (Amkar Perm), Masoud Shojaei (AEK Athens), Omid Ebrahimi (Esteghlal), Vahid Amiri (Persepolis), Ashkan Dejagah (Nottingham Forest), Saman Ghoddos (Ostersunds FK).
Forwards: Karim Ansarifard (Olympiakos), Reza Ghoochannejhad (SC Heerenveen), Mehdi Taremi (Al-Gharafa Sports Club), Alireza Jahanbakhsh (AZ Alkmaar), Sardar Azmoun (Rubin Kazan).