David Millar hailed Michael Rasmussen's expulsion from the Tour de France.
Millar served a two-year ban for using EPO
Dane Rasmussen, who was leading the Tour overall, was sacked by his Rabobank team for deceiving them as to his movements earlier in the year.
British rider Millar told BBC Five Live: "I think it's a great day. If we didn't have this out-of-competition testing this would never have arisen.
"He was playing the system. The system is not foolproof but it's getting better, and that's proven."
Rasmussen, 33, missed four out-of-competition drugs tests and had been riding under a cloud of suspiscion.
Rabobank made their decision when they were informed that the rider was in Italy in June after he had claimed to be in Mexico.
By bringing in these more stringent controls we are going to pay a higher price in the immediate future
Millar, who has become a fervent critic of drugs in cycling having served a two-year ban for using the blood-booster EPO, reserved special praise for the strong stance taken by Rabobank and their sponsors.
"You have to remember this is a sponsor that's been in the sport for years and supports the national team from a schoolboy junior level right through to professional," he added.
"The fact that they are doing something like this is a very strong statement and a very big step.
"I hope everyone is learning from it. I hope the sponsors and team management are finally learning.
"It goes to show that they are reacting rather than putting their heads in the sand. He had to go.
"This is really good for the sport. Finally team management and sponsors are assuming their responsibilities which they weren't before, which is why and how it has got to this degree.
"I think it's a really positive thing for the sport that we are getting a strong reaction and teams and sponors are taking risks like this, which they weren't before.
"We're moving in the right direction but by bringing in these more stringent controls we are going to pay a higher price in the immediate future."