SARZEAU, France >> Fernando Gaviria and Peter Sagan have turned the first four days of the Tour de France into an enthralling duel of rising star versus world champion.

And Tour newcomer Gaviria is winning so far.

Gaviria edged Sagan at the finish line to claim Stage 4 today to take his second stage win in his first participation at cycling’s greatest race.

The 23-year-old Colombian had already bettered Sagan in a sprint to take the opening stage, amid rising expectations since his four stage victories at last year’s Giro d’Italia.

Sagan hit back by winning Stage 2 in an uphill sprint after Gaviria had fallen in a group pileup on the final corner.

Tuesday’s flat leg with its four-kilometer finish — the longest straightaway to conclude a leg on this Tour— was perfect terrain for the budding rivals to break the tie.

After Quick-Step hunted down the breakaway to set up Gaviria, he powered ahead of the pack with handlebars swinging and crossed just inches ahead of Sagan and Andre Greipel in a close third.

Sagan was closing fast and seemed to be on pace to overtake him just when Gaviria hit the line.

“He is faster than me,” said Sagan, the three-time defending world champion who excels in finishes on slight ascents.

“We will see. Maybe I will wait for some mistake (to beat him). And maybe we will see the next days on the climbs. Every stage is different, every sprint is different.”

Gaviria finished the 121-mile leg from La Baule to Sarzeau that started and finished on the Atlantic coast in 4 hours, 25 minutes, 1 second.

“It was a very difficult sprint, but we knew how to pull it off,” Gaviria said. “We didn’t receive any help from the other teams to bring the breakaway back, but at the end my team deserves this victory and we can go to the hotel very happy with what we achieved.”

Defending champion Chris Froome of Sky, who remained 55 seconds back due to his fall in Stage 1, finished safely in the pack with leader Greg Van Avermaet.

Riders were enjoying a calm sunny afternoon until a pileup near the front of the peloton with just over 5K left that sent several riders to the tarmac.

But there were no changes among the title hopefuls.

Van Avermaet, the 2016 Olympic road race champion who is support rider for BMC leader Richie Porte, took the yellow jersey when his team won Monday’s team time trial.

Tom Dumoulin was seventh (11 seconds behind), last year’s runner-up Rigoberto Uran was 10th (:35) and Porte 14th (:51). Movistar teammates Alejandro Valverde and Mikel Landa were 15th and 16th (:53), narrowly ahead of Froome. The 2014 champion Vincenzo Nibali was 19th (1:06), Romain Bardet 20th (1:15) and Nairo Quintana was 48th (2:08).

A four-man breakaway opened up a gap of more than seven minutes early on, but they were slowly reeled in by the Quick-Step-led pack with 2 kilometers to go.

The Tour will spend three more days in northeastern Brittany, where fans waved black-and-white striped Breton flag on the roadside as the peloton rolled through the country villages.

Next up is Stage 5, a hilly 204.5-kilometer leg from Lorient to Quimper.

“Tomorrow is going to be a hard stage. It is a mini-classic in the Tour,” said Van Avermaet.

The Tour works its way east before hitting the feared cobblestones of Stage 9 and then heading south and into the mountains.

Froome, who was cleared of doping allegations last week by the International Cycling Union, has been jeered by some skeptical fans since arriving in France. During Tuesday’s stage, several syringes were seen alongside the course route in apparent protest by anti-Froome spectators.

Froome is trying to join the select group of Jacques Anquetil, Eddy Merckx, Bernard Hinault and Miguel Indurain as the only riders to win the Tour five times.

The three-week Tour ends July 29 in Paris.