In a tweet signed off by William posted on the official Kensington Palace page, he said: "I couldn't be prouder of #England- a victory in a penalty shootout!"
'I actually predicted we would get knocked out to Colombia in the last 16 so I was already anxious.
Zlatan continued: "But they believe in themselves and have a strong sense within the group".
"Yes, I think Sweden can become world champions, just like I said before the World Cup started", said Zlatan, as quoted from the Swedish newspaper Expressen website. Sweden is another team we have a poor record against.
Gareth Southgate's England side face Sweden in Samara on Saturday.
Kane-led England favourites against Colombia
The Three Lions were moments away from a 1-0 win after 90 minutes, but Yerry Mina's header ensured the game went to extra time . He said: "There's some big teams gone out of the World Cup and this could be the year England can go far and hopefully win it".
"Everyone gets anxious when a game goes to penalties, and with the record England have in competitions, it's huge in England that they've managed to win the shootout here.it's great for confidence because of England's history", he said.
England had lost six of their past seven shootouts - at the World Cup in 1990, 1998 and 2006 and the European Championship in 1996, 2004 and 2012 - and not even won a knock-out tie since 2006.
Southgate also said he would not be able to trust his players' word to see if they're really fit, as everyone wants to play in games of such magnitude.
Preparation has been key for England at this World Cup, having not only have flourished from set-pieces but time spent strategising for shootouts.
"That hasn't been good for us".
The biggest-ever audience is 26.2m for England's semi-final against West Germany in 1990.
It was also no doubt a proud moment for his former 'keeper coach at Deepdale Alan Kelly who reacted to the criticism Pickford had received just days prior.