He rode straight into them.
Roadside spectators on the hairpin bend both froze and scattered as the burly Welshman barrelled toward them. Braking frantically, one shoe unclipped from his pedals, the right-hand man for race leader Chris Froome tried to shave off speed.
A spectator's folded plastic chair flew as the racer for Team Sky careened into the pole, shoulder and helmeted-head first. Thomas bounced off it like a tossed rag doll and disappeared over a drop-off into a dark thicket of woods.
"I was all tangled up in the bushes," he said. "A nice Frenchman pulled me out."
At least he finished Stage 16 with his sense of humour intact. Asked if he still remembered his name, Thomas jokingly replied: "Chris Froome."
Had it really been race leader Froome, not Thomas, who crashed on the stage's hair-raising final descent in the foothills of the Alps, their Team Sky bosses wouldn't have seen the funny side.
Surviving the tortuous downhill bends raced at speeds of 70 kph (45 mph) or more with his body and race lead still in one piece means that Froome now only has four days of climbing to get through before the British rider sips a flute of champagne Sunday on the Champs-Elysees.
Outwitting Peter Sagan, who took heart-in-the-mouth risks on the descent, Spanish rider Ruben Plaza Molina rode triumphantly into the finish at Gap as the solo winner. Crossing the line, Plaza sucked his right thumb as a wink to his young son.
The Lampre-Merida rider reached the top of the stage's last climb with about a minute's lead on Sagan, who rides for Tinkoff-Saxo. As they both sped down, with Sagan gaining, Plaza's team kept him updated on the time-gap via his earpiece radio.
"That allowed me to go down quickly, but still carefully," Plaza said. "The descent is very, very dangerous."
Plaza and Sagan are not challengers for the podium in Paris, which is why Froome let them get away. They were part of a group of two dozen riders who rode off from the main pack, hunting for the stage win before Froome and his challengers do battle in the Alps after a rest day on Tuesday.
Victoria's Ryder Hesjedal was in 71st place, over an hour and 40 minutes behind Froome. Langley, B.C., native Svein Tuft was 167th.
Sagan beat his heart several times as he crossed the line 30 seconds behind Plaza. Sagan said he copied the chest-thump from the Leonardo DiCaprio movie "The Wolf of Wall Street." The Slovak has been a wolf on the road, constantly hunting for wins — so far without success. This was his fifth second place at this Tour.
Thomas's crash wasn't his fault. French rider Warren Barguil tried cutting the bend and collided with the Welshman, sending him on to his close encounter with the telephone pole.
"Barguil just went straight on, pushed me straight off into the lamppost and down a ditch," said Thomas. "I lost my glasses as well. They don't even make them anymore!"
The Giant-Alpecin rider was apologetic. He said he had wanted to brake but his finger slipped.
"I was very frightened," Barguil said. "I didn't do it on purpose."
Having clambered out of the bushes, Thomas remounted his bike.
"Then the mechanic came with the other one, so I jumped on that," he said. "Probably wasted a few seconds."
To be exact, 38 seconds. That's how much time he lost on the stage to Froome and other podium contenders. Froome understandably didn't hang around to see if his teammate was OK. Froome, after all, has a Tour to win, while Thomas is just his support rider.
Still, the crash is a setback to Thomas' chances of joining Froome on the podium in Paris. At the start of the stage, Thomas was 4 minutes and 54 seconds behind his Team Sky leader. Now he is 5:32 back, still in sixth place overall.
Froome's closest rival remains Nairo Quintana, trailing by 3:10. Last year's champion, Vincenzo Nibali, clawed back a few seconds by riding away from Froome's group on the last climb. But the Italian is still 7:49 off the lead, in eighth place.
Still, it could have been worse for Thomas. It was on this descent in 2003 that Lance Armstrong flew off a bend into a field and Joseba Beloki's wheels slipped on melting tarmac, throwing him to the deck and breaking bones.
Froome goes into the Alps with one less teammate, after Peter Kennaugh fell ill and abandoned.
But Thomas plans to soldier on.
"I'm sure it will take more than a knock to the head to keep him out," Team Sky manager Dave Brailsford said. "He's Welsh. People in Wales are tough."