Tens of thousands of supporters flooded the esplanade of Douala's Omnisports stadium Sunday, enduring eight hours of rain to rally behind presidential candidate Issa Tchiroma Bakary, who vowed to oust Paul Biya's 43-year rule in the October 12 election, drawing massive crowds from English-speaking strongholds like Buea and Limbé.

The 76 year old former minister and Cameroon National Salvation Front leader arrived amid throngs, his convoy mobbed as he addressed the soaked faithful.

"He is so beloved... we've never seen a crowd like this," said supporter Mohamadou Hadji, promising 100 percent victory.

Tchiroma directly taunted Biya: "You will call your opponent, chosen by the people, to concede defeat. Congratulations—you'll go down in history!"He warned the administration, electoral commission, and Constitutional Council of fraud watchdogs: the populace would seize their win "by any means" if cheated.

Supporter Taddoum Moïse echoed: "Vote for one person, monitor ballots, and proclaim Tchiroma president on October 12." The historic turnout signals opposition fire in the economic capital, though Biya's CPDM juggernaut looms large.

With 12 contenders in the fray, Tchiroma's surge tests the octogenarian's grip, fueled by economic woes and youth disillusionment in a nation craving change.