Milan - Slovenia's Primoz Roglic won the Tirreno-Adriatico race on Tuesday finishing just one-second ahead of Britain's Adam Yates after the seventh and final stage.
Roglic, 29, of Team Jumbo-Visma, had been trailing 25 seconds behind the Mitchelton-Scott rider Yates in the overall standings going into the final 10km time-trial.
"It's unbelievably close," said Roglic, who will be team leader at the Giro d'Italia for the first time.
"I felt stronger on the way back. Before the start I was confident that I'd win but I only could control myself. I'm glad it ended well."
Yates held the overall lead throughout the race after Mitchelton-Scott won the opening day team time-trial but said after the major climb stage this weekend that his 25 second lead would unlikely be enough to clinch the overall win due to Roglic being faster against the clock.
But then Yates, who will lead his team at the Tour de France, came within a hair's-breadth of the win that had viewers craning their necks at the line.
Dane Jakob Fuglsang of Astana was third overall 30 seconds adrift of the winner after the run down the flat Adriatic seafront at San Benedetto del Tronto.
European time-trial champion Victor Campenaerts of Belgium, riding for Lotto, clocked the fastest time of 11:23 early in the day to win the seventh stage just 0.03 seconds ahead of Italian Alberto Bettiol (EF Education First).
Dutchman Jos van Emden (Team Jumbo-Visma) finished the stage in third place at 4 seconds.
"I rode a perfect time-trial," said Campenaerts.
"I knew I had to be strong on the way back where the headwind was really strong.
"This victory, my first in the World Tour, is important also for my confidence in beating the world hour record next month."
Tom Dumoulin of Team Sunweb finished seventh on the day, the Dutch rider moving up to fourth overall at 1:25 ahead of French pair Thibaut Pinot (Groupama-FDJ) and Julian Alaphilippe (Deceuninck-QuickStep), who were just over 2:30 adrift in the general classification.
Former ski jumper Roglic follows his victory in the UAE Tour in the United Arab Emirates earlier this month.
Results from the seventh and final stage of the Tirreno-Adriatico cycling race, a 10.1km time-trial at San Benedetto del Tronto:
1. Victor Campenaerts (BEL/LOT) 11min 23sec (average: 55.1 km/h), 2. Alberto Bettiol (ITA/EF1) at 3sec, 3. Jos van Emden (NED/JUM) 4, 4. Sebastian Langeveld (NED/EF1) 6, 5. Yves Lampaert (BEL/DEC) 7, 6. Mads Pedersen (DEN/TRE) 8, 7. Tom Dumoulin (NED/SUN) 8, 8. Rohan Dennis (AUS/BAH) 9, 9. Michael Hepburn (AUS/MIT) 11, 10. Filippo Ganna (ITA/SKY) 12, 11. Primoz Roglic (SLO/JUM) 13.
21. Thibaut Pinot (FRA/FDJ) 24, 27. Taylor Phinney (USA/EF1) 29, 28. Tony Martin (GER/JUM) 29, 29. Greg Van Avermaet (BEL/CCC) 29, 31. Rui Costa (POR/UAE) 30, 40. Vincenzo Nibali (ITA/BAH) 36, 48. Adam Yates (GBR/MIT) 39, 61. Julian Alaphilippe (FRA/DEC) 48, 67. Peter Sagan (SVK/BOR) 51, 91. Roman Kreuziger (CZE/DDT) 1:06.
Final overall standings
1. Primoz Roglic (SLO/Jumbo) 25hr 28min 00sec, 2. Adam Yates (GBR/MIT) at 1sec, 3. Jakob Fuglsang (DEN/AST) 30, 4. Tom Dumoulin (NED/SUN) 1:25, 5. Thibaut Pinot (FRA/FDJ) 2:32, 6. Julian Alaphilippe (FRA/DEC) 2:34, 7. Wouter Poels (NED/SKY) 2:42, 8. Simon Clarke (AUS/EF1) 3:01, 9. Sam Oomen (NED/SUN) 3:12, 10. Rui Costa (POR/UAE) 3:18.
15. Vincenzo Nibali (ITA/BAH) 4:34, 16. Greg Van Avermaet (BEL/CCC) 4:57, 21. Robert Gesink (NED/JUM) 5:54, 27. Roman Kreuziger (CZE/DDT) 10:44