England started their World Cup campaign with a 6-2 victory against Iran while Gareth Bale rescued a 1-1 with the United States in Wales' return to the tournament after 64 years in opening Group B action in Qatar on Monday.
Teenager Jude Bellingham opened the scoring with his first England goal and the rampant Three Lions also delighted in a brace from Bukayo Saka, and further strikes Raheem Sterling, Marcus Rashford and Jack Grealish handed Iran their biggest World Cup defeat.
"I told you I was saving that goal, really good day and game for us. Six goals in a World Cup game is really impressive, regardless of who you play against," Borussia Dortmund's Bellingham told the BBC.
Captain Bale then rescued Wales in their first World Cup game since a 1958 debut by converting an 82nd-minute penalty against the U.S. who had led from Timothy Weah's 36th-minute strike.
England were dominant from kick-off but lost a bit of momentum after Iran keeper Ali Beiranvand suffered a head injury and received medical treatment for around eight minutes.
The keeper decided to stay on the pitch but then went down to the ground and was finally substituted in a game that saw 24 minutes of official stoppage time over the two halves.
"It was not clear at first if he had to come off," said Iran coach Carlos Queiroz. "He is now on his way to hospital to undergo further tests."
England were quick to focus back on the game and after hitting the woodwork, broke the deadlock in the 35th minute through Bellingham. Saka's first and Sterling before the break gave them a 3-0 lead at half-time.
Saka got his second in the 62nd minute before Iran pulled one back through Mehdi Taremi. But any possible threat was soon swept away once Rashford and a Grealish effort sealed the triumph, with a late Taremi penalty making it 6-2.
"I can't describe the feeling, it is amazing. I am so happy and so proud. We got the win as well so it is a really special day," Saka said.
"There was a lot of talk and speculation about our form but we showed everyone how much quality we have and what we can do."
Coach Gareth Southgate was happy with the win, but pointed out that his side "shouldn't be conceding two goals. It's a great start, but we have to be better."
Queiroz defended his players against some fans although it was not clear who exactly he meant.
"Please, the teachers, the moralists, let the kids play the game. These kids only want to play the game," Queiroz said.
The lead-up to the match was overshadowed by the captain's armband row between some European nations and the football governing body FIFA.
England's Harry Kane - and Bale later - wore official FIFA captain's armbands with the slogan No Discrimination after the ruling body had threatened seven European teams with sanctions should they wear a not sanctioned One Love armband.
English players still took a knee in a now-familiar anti-discrimination stance while Iran players didn't sing the national anthem - believed to be a gesture of support for the anti-government protests in the country.
In the other game, a determined US team took the lead against Wales when Lille winger Weah, the son of former World Player of the Year George Weah who is now President of Liberia, converted with a low shot off a superb pass from Christian Pulisic.
Euro 2016 semi-finalists Wales improved the break and came close twice before superstar Bale himself stepped up to clinch the draw in the 82nd from the spot into the top right corner after being brought down by Walker Zimmermann.
"It was a great team performance, especially in the second half when we showed that real grit and determination to get back into the game. We are proud of that. We have things to build on and things to work on," Bale said.
Coach Robert Page told ITV: "It was 64 years but worth the wait.
"When we got the penalty we knew who was taking it, one million percent. He’s never let us down has he? It’s all about Bale and rightly so."
Group B continues on Friday with Wales v Iran and England v U.S.
