Croatia qualified for Euro 2020 after second-half goals from Nikola Vlasic, Bruno Petkovic and Ivan Perisic inspired a comeback 3-1 home win over Slovakia in a pulsating Group E qualifier on Saturday.
The result left the Croatians on 17 points from eight games as they completed their campaign, with three sides behind them still in contention for next year's 24-nation tournament.
Second-placed Hungary (12 points) visit third-placed Wales (11 points) on Tuesday in a dogfight for a top-two finish where a win would see either through.
A draw, however, could allow fourth-placed Slovakia (10 points), who are at home to bottom team Azerbaijan in their final game, to squeeze through as they have a better head-to-head record against the Hungarians.
Croatia coach Zlatko Dalic, who guided them to a runners-up finish at the 2018 World Cup, was delighted.
"I am proud and I congratulate the players for winning the group and qualifying," he said.
"I wasn't worried when we fell behind because we were playing well and it was much easier after we equalised.
"All credit to the fans too who turned up in numbers and I hope we will bring more joy to Croatia in the European Championship."
Petkovic added: "We vowed not to lose our heads if we conceded first and managed to turn it around because we kept our composure. This young team has a very good chemistry."
Croatia squandered a flurry of first-half chances and were punished in the 32nd minute when Robert Bozenik turned in a Stanislav Lobotka cross from the left.
Bozenik almost doubled Slovakia's lead as Croatia keeper Dominik Livakovic just managed to tip over the 19-year-old striker's ferocious drive from the edge of the penalty area.
Yet that was as good as it got for Slovakia on a rainy night in the coastal city of Rijeka, as Croatia turned the tide with a fierce second-half onslaught.
Vlasic equalised in the 56th minute with a low drive from 20 metres and Petkovic fired Croatia ahead four minutes later when he powered an unstoppable header into the top corner after Luka Modric swung in an inch-perfect corner.
Slovakia had winger Robert Mak sent off in the 66th minute for a second bookable foul before Perisic added the third for the home side, volleying home a Borna Barisic assist to delight a packed home crowd in Rujevica stadium.
Slovakia keeper Martin Dubravka spared Slovakia a heavier defeat with several fine saves in the closing stages.