CAIRO — After a lifetime of being told who will rule them, Egyptians dove enthusiastically into the uncertainty of the Arab world’s first competitive presidential election Wednesday. Up to the last minute, voters wrestled with a polarizing choice between secularists rooted in Hosni Mubarak’s old autocracy and Islamists hoping to enfuse the state with religion.

The choices in the race raised worries among many observers whether real democracy will emerge in Egypt. And the final result, likely to come only after a runoff next month, will only open a new chapter of political struggle.

But in the lines at the polls, voters were palpably excited at the chance to decide their country’s path in the vote, which is the fruit of last year’s stunning popular revolt that overthew Mubarak after 29 years in power.

For the past 60 years, Egypt’s presidents running unchallenged have largely been re-affirmed in yes-or-no referendums that few bothered to vote in.

Mohammed Salah, 26, emerged grinning from a poll station, fresh from casting his ballot. “Before, they used to take care of that for me,” he said. “Today, I am choosing for myself.”

Medhat Ibrahim, 58, who suffers from cancer, had tears in his eyes. “I might die in a matter of months, so I came for my children, so they can live,” he said, waiting to vote in a poor Cairo district. “We want to live better, like human beings.”

Adding to the drama, this election is up in the air. The reliability of polls is unsure, and four of the 13 candidates have bounced around the top spots, leaving no clear single front-runner.

None is likely to win outright in Wednesday’s and today’s balloting, so the top two vote-getters will enter a run-off June 16 and 17, with the winner announced June 21.

The two secular front-runners are veterans of Mubarak’s regime, former prime minister Ahmed Shafiq and former foreign minister Amr Moussa.

The main Islamist contenders are Mohammed Morsi of the powerful Muslim Brotherhood and Abdel-Moneim Abolfotoh, a moderate Islamist whose inclusive platform has won him the support of some liberals, leftists and minority Christians.