Debra Jefferies, a cocktail waitress at the Horseshoe Las Vegas, spent much of the week wondering whether she would be walking a picket line, as she did in 1984 — the last time there was a major strike among hospitality workers in the city.

“There was solidarity back then, just like there has been right now,” said Ms. Jefferies, 68. “Each generation has stepped up to demand better working conditions.”

Nearly 35,000 union members, including Ms. Jefferies, had threatened to begin a strike on Friday against the city’s three big casino operators after months of negotiations had failed to yield a new five-year labor agreement.

But last-minute maneuvering averted a walkout as the resort owners — Caesars Entertainment, MGM Resorts International and Wynn Resorts — came to terms, one by one, on tentative contracts with the city’s two most powerful unions.

The final agreement, with Wynn Resorts, came early on Friday, a few hours before the strike deadline. The deal, when ratified, would provide “outstanding benefits and overall compensation to our employees,” Wynn said in a statement. The culinary union said the contract featured the largest wage increase negotiated in its 88-year history.

A strike loomed as a major disruption to a series of big events, starting with the Las Vegas Grand Prix, a Formula 1 auto race along The Strip that is expected to draw hundreds of thousands of visitors late next week.

It was the latest crucible for Las Vegas and for Nevada, which has the highest unemployment rate in the nation — currently 5.4 percent — and has struggled to bounce back ever since the start of the pandemic shuttered The Strip for months.

Along with the Formula 1 race, Las Vegas is the site of the National Finals Rodeo in December and the Super Bowl in February.

Bill Hornbuckle, the chief executive of MGM, said in a Wednesday earnings call that his company had sold more than 10,000 tickets to the Grand Prix and expected to bring in $60 million in extra hotel revenue in the days ahead.

The dispute pitted Culinary Workers Union Local 226 and Bartenders Union Local 165 — affiliates of the labor confederation UNITE HERE — against Caesars, MGM and Wynn, which operate 18 hotels along the The Strip and are the state’s three biggest employers. Ted Pappageorge, the head of Local 226, likened the negotiations to landing “three large planes at once.”

The unions pushed for contracts that would raise wages, bolster safety practices and ease concerns about the introduction of new technology that could affect jobs.

“Hospitality workers will now be able to provide for their families and thrive in Las Vegas,” Mr. Pappageorge said, adding that the MGM Resorts contract would provide compensation increases “far above” those in the last contract, which amounted to a $4.57-an-hour increase in overall in wages, health care and pensions.

Details of the tentative agreements have not been released, but the terms are expected to be similar across the three companies. Under the contract that expired Sept. 15, union members make $26 an hour on average.

Stephen M. Miller, an economics professor at the University of Nevada, Las Vegas, said the sea change in the balance of power between management and labor that has occurred in the post-pandemic period is on clear display in Las Vegas.

Mr. Miller said the government stimulus money during the pandemic gave laid-off workers, including many who worked in the culinary union in Las Vegas, the resources to reconsider their future employment path.

“The labor market is involved in a large restructuring process, which has given labor more bargaining power,” Mr. Miller said. “The resurgence of strikes and threats of strikes is the observable outcome of that power shift.”

Even before the labor ferment in the last year in the auto industry, Hollywood and other realms, Nevada’s culinary workers were a particularly powerful force.

It was culinary union members — who include housekeepers, cooks, doormen, laundry workers, bartenders and food servers — whose political clout was vital in winning legislative approval of Covid-19 safety precautions.

And they often help sway elections as a powerful base for Democrats.

In 2020, members knocked on more than 500,000 doors and helped Joseph R. Biden Jr. win the state by roughly two percentage points. Last year, during the 2022 midterms, they doubled their door-knocking efforts, helping Sen. Catherine Cortez Masto secure her re-election. (Despite their efforts, incumbent Democratic Gov. Steve Sisolak, who faced fierce criticism over pandemic shutdowns, lost by a narrow margin.)

That kind of support may be crucial to Mr. Biden again next year in a swing state where a recent New York Times/Siena College poll showed him trailing his likely Republican opponent, former President Donald J. Trump, by 10 percentage points.

Yusett Salomon was among the workers who knocked on doors for Democrats during the 2022 election. He has worked as a warehouse operator transporting pallets of food and plants at the Wynn for the past two years, earning $22 an hour.

On Thursday, Mr. Salomon sat inside a cavernous hotel conference room observing negotiations. “There is no better time than now to fight for what we deserve,” he said.