A seven-point advantage over his only challenger, Ferrari's Felipe Massa, means he can afford to finish as low as fifth and still claim the drivers' crown even if Massa wins in front of his home crowd.
What impressed Stewart was the manner in which Hamilton rebounded from his first-corner blunder the previous weekend.
Stewart said: "In Japan, Lewis got flustered by his car not coming off the line in the appropriate fashion and I'm afraid he had a drop-out of mental control. That's what caused the subsequent eruption.
"Yesterday, he was cool on the start and the car came right for him. Lewis was very mature and calculated.
"Ferrari will now put an enormous effort together for Brazil. But even if they win the race they're not going to win the championship if Lewis keeps his car on the road.
"If he stays out of trouble and nurses the car home he's going to win the world championship and he will thoroughly deserve it if that happens. But nobody can take anything for granted."
Dennis has sufficient experience to acknowledge Stewart's concern. And even though winning races is his only creed, the McLaren boss is willing to give away the chequered flag at Interlagos in order to secure the bigger prize.
He said: "I have no problem with Massa coming first and Kimi Raikkonen coming second. It doesn't really worry us, even though we don't think Ferrari are going to have a performance advantage.
"We will compete fiercely through practice and qualifying, see where we are and take a view from there.
"The outcome depends on where the other cars are, but we go to Brazil knowing we can finish third, fourth or fifth. Our target will be to finish the race and do what we have to do to win the championship. The most important thing will be to stay out of trouble."
Hamilton maintained his focus brilliantly in Shanghai to win from pole position, leaving Massa so far behind that he had to depend on Raikkonen conceding second place in order to keep the damage to his fading title challenge to a minimum.
"Lewis did a truly fabulous job," said Dennis. "He thrives on pressure and if there is a challenge to his integrity it only makes him stronger."
