BRUSSELS -- Mike Teunissen claimed the first yellow jersey of this year's Tour de France with a sprint victory in Saturday's opening stage, which was marked by defending champion Geraint Thomas' crash in the finale.

Thomas' Ineos team said he fell in the final meters but "feels fine." Another top contender, Jakob Fuglsang, also hit the tarmac about 20 kilometres (12 miles) from the finish in a separate crash.

The 26-year-old Teunissen, who became the first Dutch rider to wear the yellow jersey since Erik Breukink 30 years ago, edged former world champion Peter Sagan and Caleb Ewan on the finish line in Brussels.

Thomas quickly got back on his bike after hitting a barrier while his teammate Egan Bernal was held up by the crash. They did not lose time as per race regulations because the accident occurred within the final three kilometres.

In the absence of four-time winner Chris Froome, Thomas and Bernal have been promoted to co-leaders of the Ineos team.

Fuglsang, who is rated among the favourites this year, was hurt in the crash that took place a few moments earlier. The Criterium du Dauphine winner remounted his bike with blood on his face and right knee, and scratches on his jersey.

The race started from the Belgian capital to honour the 50th anniversary of cycling great Eddy Merckx's first of five Tour victories. The 194.5-kilometre (120.8-mile) trek took the peloton through the Flanders and Wallonia regions and back to Brussels, which will also host Sunday's team time trial.

The second spill played havoc within the sprinters' teams riding at the front and split the peloton in two. It took out of contention Teunissen's Jumbo-Visma teammate Dylan Groenewegen, the team's best sprinter.

"Bizarre scenario. I hope Dylan is OK," said Teunissen, who was initially set to be part of Groenewegen's lead-out train.

In the slightly uphill section leading to the finish line on the leafy Avenue du Parc Royal, Teunissen perfectly timed his effort to deny Sagan a 12th stage win at the Tour.

The opening day had started in a joyful atmosphere in the cycling-mad city of Brussels. Merckx was greeted by Belgian fans filling the streets as he stood alongside race director Christian Prudhomme in a red open-top car riding in front of the peloton.

The five-time Tour champion saluted the crowd and chatted with competitors before a short stop on Brussels' Grand Place where Prudhomme introduced riders to King Philippe of Belgium and Prime Minister Charles Michel.

Leaving Brussels, the 176 Tour competitors started their loop south of the city at a fast tempo as a group of four riders led by Greg Van Avermaet, a one-day classics specialist from Belgium, immediately formed at the front.

The quartet reached the first difficulty of the day -- the Muur van Geraardsbergen, a 1.2-kilometre cobbled climb -- with a 3-minute lead. Van Avermaet made a point of honour to be first at the top to the delight of home fans cheering him along on the side of the road. Belgian rider Xandro Meurisse, a member of the initial breakaway, was first at the Bosberg, another climb featuring at the Ronde van Vlaanderen classic race.

Guaranteed the first best climber's polka dot jersey, Van Avermaet stopped his effort soon after and was reined in by the peloton as the lead group was reduced to three men: Meurisse, Natnael Berhane and Mads Wurtz.

Behind them, sprinters' teams organized the chase to reduce the gap to less than two minutes with 90 kilometres to go. As the main pack approached a two-kilometre long and dangerous cobbled sector outside of the city of Charleroi, Thomas and other contenders also surged to the front in a move aimed at avoiding potential crashes on a narrow stretch of road.

The only noteworthy incident on the tricky section was Deceuninck-Quick Step sprinter Elia Viviani's puncture. The Italian rider was held back for a while and could not compete with the fastest men for the intermediate sprint points once the three at the front were caught with 70 kilometres left.

Sagan, chasing a seventh best sprinter's green jersey this year, used his power and speed to beat Sonny Colbrelli and Van Avermaet.

Tour debutant Stephane Rossetto of France then tried a solo escape and was first at the Lion's Mound monument that overlooks the battlefield where Napoleon's troops were defeated at the Battle of Waterloo. But the Frenchman's efforts on open stretches of road exposed to wind were left unrewarded and he was ultimately swallowed up as the final sprint took shape.