He was speaking as it emerged Britain's David Millar, dogged by injury and bad luck, was out of the Tour.
American Armstrong launched a devastating attack on the Alpe d'Huez and moved up to fourth in the overall standings, relaunching his bid for a third successive victory in the race.
But he had earlier appeared to be in trouble on the ascent to Glandon and was slipping behind Jan Ullrich's Telekom team at one stage.
"Maybe it was a bluff," said the US Postal rider. "Telekom decided to lead the pack and mark the rhythm going into the mountains.
"With my team mates (Roberto) Heras and (Jose Luis) Rubiera we decided to keep quiet and play poker.
"Today in cycling, everyone can watch TV at the finish line, in the press centre, in the team hotels and in the cars. Above all the team sporting directors can watch.
"Sometimes you have to play that game a little bit. Our team wasn't in a position to do the work so it was better that Telekom continued to work and I continued to suffer."
Armstrong said he was "honoured" to win the classic stage finish in L'Alpe d'Huez but warned he still had a lot of work to do to claim overall victory.
Andrei Kivilev of Kazakhstan went 13 minutes clear of Armstrong on Sunday and still has an advantage in excess of eight minutes.
"This is a very special stage," Armstrong said. "It means a lot to everyone in cycling and it's probably the most famous climb.
"That motivated me. I didn't set out to try and take time off my rivals - just to win. The scary thing is that that was everything I had today. I couldn't have gone any harder."
Despite his magnificent effort on stage 10, Armstrong believes the 32km uphill time trial set for Wednesday could be crucial if he is to get closer to the yellow jersey.
"I might pay for this effort," Armstrong warned. "I might lose two minutes tomorrow. I hope not. I know the course and I won a mountain time trial in the Tour of Switzerland, but we'll see.
"As for Kivilev, he's a damn good rider and I tried to get him on our team last year. I respect him a lot and he could be a tough guy to catch. We may have made a big mistake on Sunday."
For Cofidis rider Millar, the 2001 Tour has been a bitter experience.
He had bravely hung in since injuring his leg in a crash on the first day, but has finally quit.
The 24-year-old had spent most of the Tour as the 'lantern rouge' - the last-placed rider.