Thomas won stage 11 in La Rosière on Wednesday and took the race lead thanks to an attack with 5.5km to go. He caught the stage leaders and gained time on his general classification rivals.
He now leads by 1-25 minutes over Froome and 1-44 over Dutchman Tom Dumoulin (Team Sunweb) after 11 days of racing. Tomorrow, they face the final day in the Alps and a summit finish up Alpe d’Huez before transfer stages to the Pyrenean mountains.
“Obviously Froomey is the leader, he’s won six Grand Tours,” Thomas said. “For me it’s an unknown, it’s more just trying to get through the stage, stay in the position we were in at least and not lose time on GC.”
Thomas won the Critérium du Dauphiné ahead of the Tour de France while Froome recovered from his Giro d’Italia victory. Even with the famous yellow jersey on his shoulders for a second time after winning the opening stage in 2017, he stays focussed on Froome’s chances.
“Froomey knows how to win a three-week race, he’s still the leader. For me, whatever happens now it’s been a successful Tour, it’s been amazing feeling to win the stage and take the jersey. I’m super happy with that,” Thomas said.
“Obviously I’d love to stay up on the podium as long as possible but the main thing is winning and Froomey is our best chance. There’s still half the race to go.”
Watch: Tour de France 2018 stage 11 highlights
Thomas was the best placed overall favourite coming into the 11th stage. He attacked at 5.5km out from the finish to reel in Tom Dumoulin and catch Mikel Nieve (Mitchelton-Scott) for the stage win.
“[The attack] was more opportunity, more instinct for myself when Kwiatkowski was done with his turn,” Thomas said. “It meant Froomey could follow behind and I managed to get across to Dumoulin, then I could sit on him so it was an ideal scenario.”
Asked what he would do if he was in Froome’s shoes, he said, “I probably would have ridden with Dan as well. It’s just a good position for the team.”
Thomas may have sung the praises for Froome, saying is the “best chance” for Team Sky, but some wondered if he really meant it or secretly kept hopes to win the 2018 Tour himself.
“It’s just how I feel. Some guys might sit here and give some PR bulls*** but I just say it how it is with me, and that’s how it is. Froomey is the leader,” Thomas said.
“For sure I’m not going to sit up and lose time, but I think we’re in a great position. It’s just a bit of an unknown for me to race over three weeks. It’s the ideal scenario at the moment and long may it continue.”
Thomas has always suffered from one incident or another when racing for the general classification in a Grand Tour. Last year, he abandoned the Giro d’Italia after being involved in a collision with a race motor bike early in the race, while he also crashed out of the Tour while sitting second overall on stage nine.