Gareth Bale says beating Russia 3-0 at Euro 2016 was the best performance he has been involved in for Wales.
Wales will play the third-placed team from Group A, C or D at the Parc des Princes in Paris on Saturday.
"It's incredible. It's a dream for all of us. What an amazing way to do it," said forward Bale.
"We knew everything was on this game. It was in our own hands and we said to go out there, enjoy ourselves.
"The performance was probably the best I've ever been involved in since I've been here. And what support."
Aaron Ramsey and Neil Taylor scored before Bale capped a dominant Wales display by poking past Russia goalkeeper Igor Akinfeev in the second half, his third goal in as many games.
He is the leading scorer at Euro 2016 and the top scorer for Wales in a major international tournament, surpassing Ivor Allchurch's two goals at the 1958 World Cup.
"We started very well; we didn't feel too nervous at the start. We were very confident and to top the group, what more can you ask?" added Bale.
"We said we didn't want to come here and just make up the numbers and to win the group, we can't do any more than that.
"Now we look forward to who we've got next."
Bouncing back after England defeat
Wales boss Chris Coleman, whose side began the game second in the group after their 2-1 defeat by England on Thursday, praised their "brave" display against Russia.
"The three points are massive for us but the performance was even sweeter than the points," said Coleman.
"The players were brave. I don't mean brave in terms of without the ball; I mean possession. They did everything that they are capable of doing in possession.
"We didn't do that against England. They were brilliant without with ball but with the ball we never played like we can play, as we showed tonight."
Group winners and beyond
Wales' opponents in the first knockout phase will be confirmed on Tuesday, when the final round of Group C and D games are played. Albania finished third in Group A.
"It's not the end of the tournament," said Coleman. "This group of players are on the way to something else; they're on the way to some more success.
"This is the part of the journey they're on and me and my staff are just glad we're on it with them."
How far can Wales go?
Playing in their first major tournament for 58 years, Wales have scored more goals than any other team in the competition.
Despite a potential meeting with world champions Germany in the quarter-finals, Coleman said his side "have nothing to fear".
He added: "We respect everybody and, when we play like that, why should we have any fear?"