Andy Murray guided Great Britain back to the Davis Cup World Group for the first time since 2008 with victory over Croatia's Ivan Dodig on the Umag clay.
The Wimbledon champion beat Dodig 6-4 6-2 6-4 to give Britain an unassailable 3-1 lead in the best-of-five play-off.
Murray, 26, was untroubled by the world number 35 and showed no signs of a recent back injury.
British number two Dan Evans won his dead rubber against Mate Pavic 6-4 7-6 (7-4) to clinch a 4-1 triumph.
World number three Murray, playing his first Davis Cup tie for two years, was instrumental in Britain's success, winning both his singles matches and combining with Colin Fleming to win Saturday's doubles rubber.
Britain will face another of the world's top 16 nations in the first round of the World Group in February, with the draw taking place on Wednesday.
And Murray is eager to be involved.
"If I'm fit and healthy, I will be there to play," the British number one told BBC Sport. "A couple of years ago that wasn't the case when I sat down with [captain] Leon Smith.
"I wanted the younger guys to step up and experience it. There was no use us being in the World Group because we weren't ready for it.
"But now I think we are ready to do well. We have a top doubles team. Dan (Evans) and James (Ward) will continue to improve and we've got the makings of a very solid team."
After breaking Dodig, 28, in the first game of their match, Murray was pegged back to 2-2 before immediately breaking again.
From then on, the Scot dictated play to win the first set in 47 minutes before rattling through the second with a double break.
The match ended amid controversy when a Dodig winner, which would have given him a break point, was overruled by the umpire after Murray pointed to a mark on the clay.
The home crowd booed as Murray won the ensuing match point before celebrating on court with his team-mates.
"I thought it was a pretty good match. I gave him very few opportunities on my serve," added Murray.
"It got pretty hostile towards the end. It was good to go through in that kind of atmosphere. You don't see that much in Grand Slam matches, and it is good for character-building.
"The thing is, when the crowds get like that you have to tell yourself it's because they are frustrated that their team is losing. I managed to stay cool at the end."
Looking ahead to the draw, Murray said: "I would just like a home tie, in a big arena, against one of the top teams.
"It is an incredibly difficult competition to win because some of the teams have so much depth. It depends on the ties and whether you are at home.
"We could easily draw Spain away in the first round and that would be an ugly match-up for us - very difficult to win.
"But it's possible to go deep into the competition. Let's enjoy this just now and wait and see the draw on Wednesday."
Captain Smith, who has won seven of his eight ties since his appointment in 2010, paid tribute to Murray's role in the success.
"Andy is such a good player and so experienced," said Smith. "I did not have to say much, so it was more putting an ice towel round his neck.
"It was more about knowing when to say things, rather than just blurting things. Everyone has played a big part in this, and I hope that everyone has bought into the team spirit."