The member of the Dutch team LottoNl-Jumbo, who took silver in the 2017 UCI Road World Championships time trial, laid the foundations for the win in Saturday's fourth stage, which brought him the overall lead and a 33 second advantage in the overall standings.
After blowing away the competition in the key mountain stage, Roglič won today's 21.5 km time trial with a time of 24 minutes and 46 seconds, 27 seconds ahead of the Slovenian national time trial champion Jan Tratnik.
Roglič, who also became in 2017 the first Slovenian with a Tour De France stage win while moreover winning this year the Tour of the Basque Country, won the overall classification ahead of Colombia's Rigoberto Uran in second and Slovenia's Matej Mahorič in third place.
"What can I say, it is hard to compare victories ... I'm honoured I was able to win the Tour of Slovenia for a second time. This is for all the people who cheered for us along the road. I'm happy the victory ended up staying in Slovenia," Roglič said after the race.
He said the challenge in Slovenia has also been a preparation for the Tour de France, announcing he would again be eyeing stage victories in the Alps and Pyrenees as opposed to a top result in the overall classification, which would be the job of his teammate Steven Kruijswijk.
"I'm looking forward to the second and third week ... I'll try to get as much experience as possible, learn, be focused," explained Roglič, who is expected to soon also start targeting the top position overall in one of the major three-week races.
The former ski jumper was the favourite of this-year's Slovenian tour, which featured 22 teams, including a record nine teams from the UCI World Tour, the highest category in professional road cycling. It was the first time that it spanned over five stages.
Slovenian cyclists, whose last of what are now 12 Slovenian overall victories at the home event dated back to 2015, left an excellent impression. Apart from Roglič and Mohorič making the podium, Tadej Pogačar claimed the jersey of the best young cyclist for the second year in a row.
* Results, 5th stage: 1. Primož Roglič (Slo/LottoNL-Jumbo) 24.46 2. Jan Tratnik (Slo/CCC Sprandi Polkowice) +0.27 3. Josef Černy (Cze/Elkov) 0.35 4. Jack Bauer (Aus/Scott) 0.38 5. Tom Scully (Aus/Cannondale-Drapac) 0.43 6. Luke Durbridge (Aus/Scott) 0.46 7. Roger Kluge (Ger/Scott) 0.47 8. Alex Dawsett (GBr/Katjuša) 0.51 9. Vegard Stake Laengen (Nor/Emirates) 0.52 10. Nils Politt (Ger/Katjuša) 0.55 ... 14. Tadej Pogačar (Slo/Ljubljana Gusto Xaurum) 1:16 18. Matej Mohorič (Slo/Bahrain-Merida) 1:22 ... - final overall: 1. Primož Roglič (Slo/LottoNL-Jumbo) 15:18.13 2. Rigoberto Uran (Col/Cannondale-Drapac) 1.50 3. Matej Mohorič (Slo/Bahrain-Merida) 2.14 4. Tadej Pogačar (Slo/Ljubljana Gusto Xaurum) 2.16 5. Michael Storer (Aus/Sunweb) 2.18 6. Rafal Majka (Pol/Bora-Hansgrohe) 2.21 4. Ildar Arslanov (Rus/Gazprom RusVelo) 0.48 7. Josef Černy (Cze/Elkov) 3.09 8. Janez Brajkovič (Slo/Adria Mobil) 3.15 9. Ildar Ruslanov (Rus/Gazprom RusVelo) 3.15 10. Vegard Stake Laengen (Nor/Emirates) 3.16 ...