Toulouse - Colombian Nairo Quintana kept his overall lead in the Route du Sud as his Spanish Movistar team-mate Marc Soler won Saturday's fourth stage.
Quintana skipped the traditional Tour de France warm-up events - the Criterium du Dauphine and Tour of Switzerland - to concentrate on altitude training in the mountains back home in Colombia.
But he came to the four-day Route du Sud for some race practice and now must simply hold onto his lead in Sunday's final stage to claim the overall crown for the second time.
Quintana, who was second to Chris Froome at the Tour de France in 2013 and 2015, will be among the favourites for the Grand Boucle, which starts in two weeks.
The 26-year-old winner of the 2014 Giro d'Italia has been in fine form this year, winning the tours of Romandie and Catalunya, while finishing third in the Basque Country and San Luis.
Soler made a solo break to victory at the end of Saturday's 184.9km Pyrenean stage from Saint-Gaudens to Val d'Azu Couraduque.
Quintana tracked Hugh Carthy up the final climb before outsprinting the Briton for second place, four seconds behind his team-mate.
Quintana leads Soler by 36 seconds with Carthy third overall at 58 seconds.
Results after the 184.9 km fourth stage of the Route de Sud cycling
race between Saint-Gaudens and Val d'Azun-Couraduque on Saturday:
1. Marc Soler (ESP/Movistar) 5hr 36min 13sec, 2. Nairo Quintana Rojas
(COL) at 4sec, 3. Hugh Carthy (GBR) 4, 4. Nicolas Edet (FRA) 17, 5.
Thomas Voeckler (FRA) 21, 6. Sergio Pardilla Bellon (ESP) 33, 7. Ricardo
Vilela (POR) 55, 8. Mikel Bizkarra (ESP) 57, 9. Luis Angel Mate
Mardones (ESP) 57, 10. David Arroyo Duran (ESP) 1min 25sec
1. Nairo Quintana Rojas (COL/Movistar) 12hr 52min 55sec, 2. Marc
Soler (ESP) at 36sec, 3. Hugh Carthy (GRB) 58, 4. Nicolas Edet (FRA)
1:06, 5. Thomas Voeckler (FRA) 1:15, 6. Sergio Pardilla Bellon (ESP)
1:55, 7. Ricardo Vilela (POR) 2:01, 8. Mikel Bizkarra (ESP) 2:12, 9.
Stéphane Rossetto (FRA) 2:20, 10. Luis Angel Mate Mardones (ESP) 2:36