Since breaking the world record last September in Paris, Montgomery courted controversy through a brief alliance with sprint coach Charlie Francis.
Francis has been banned for life by the Canadian federation after admitting he administered drugs to Ben Johnson who tested positive after winning the 1988 Seoul Olympic 100 title.
Montgomery's life took another twist when Jones gave birth to their son in June and his subsequent form has veered between the indifferent and the awful.
He failed to even make the final at the London grand prix this month and shortly afterwards cut short his European season, saying a peanut allergy had affected his immune system.
Written off before the championships started on Saturday, Montgomery belied his recent form with impressive performances in the opening two rounds on Sunday.
He clocked 10.07 in the first round, equalled his own season's best of 10.04 in the second and looked to have plenty in reserve.
FAVOUR
Triple Olympic champion Jones, the world 100 champion in 1997 and 1999, believes Montgomery's poor recent form may work in his favour.
"I think, if anything, the pressure is now off Tim," she said. "Earlier in this season, he was
"Now it seems as if everyone is counting Tim out of it. (If) you know anything about Tim Montgomery's career, you know that as soon as you count him out, he's going to do something fabulous.
"You know, last year at the grand prix final he set the world record. Nobody expected that."
Defending champion Maurice Greene, who lost his world record to Montgomery, clocked 10.18 in the first round on Sunday before improving to 10.04 in his second round heat, 0.02 of a second behind Commonwealth champion Kim Collins.
Five other titles will be decided on Monday, with the women's pole vault promising to deliver drama equivalent to the 2001 final.
After a four-hour duel in the afternoon sun in Edmonton, Stacy Dragila finally prevailed over her Russian rival Svetlana Feofanova with just one missed attempt at 4.65 metres proving the difference.
A world record and a bonus of $100,000 is possible on Monday with record holder Yelena Isinbayeva of Russia in the field.
Win or lose, Monday men's triple jump final will be the last outing for Britain's world record holder Jonathan Edwards.
At the age of 37, Edwards's body has told him to retire.
"I don't feel that emotional about things, not yet anyway. I'm feeling good, my ankle is holding up and I plan on being there tomorrow," he said.