WASHINGTON — In a surprising victory for former president Barack Obama’s environmental legacy, the Senate voted Wednesday to uphold an Obama-era climate change regulation to control the release of methane from oil and gas wells on public land.

Senators voted 51-49 to block consideration of a resolution to repeal the 2016 Interior Department rule to curb emissions of methane, a powerful planet-warming greenhouse gas. Senators John McCain of Arizona, Lindsey Graham of South Carolina, and Susan Collins of Maine, all Republicans who have expressed concern about climate change and backed legislation to tackle the issue, broke with their party to join Democrats and defeat the resolution.

The vote also marked the first, and probably the only, defeat of a stream of resolutions over the last four months — pursued through the once-obscure Congressional Review Act — to unwind regulations approved late in the Obama administration.

In anticipation of Republican defections, President Trump sent Vice President Mike Pence to the Senate floor to break a tie vote. But with three members of his own party breaking away, Pence stood aside.

“We were surprised and thrilled to win on this,’’ said Tiernan Sittenfeld, senior vice president of the League of Conservation Voters, which, along with other environmental groups, has been lobbying Republicans for weeks to vote against the repeal of the methane rule. “This is clearly a huge win for our health and our climate.’’

The Independent Petroleum Association of America, which represents smaller oil and gas producers, criticized the vote. “We’re disappointed the Senate wasn’t able to stop President Obama’s unworkable rule by a federal agency that does not have the congressionally granted authority to regulate air quality,’’ said Barry Russell, the group’s president.

The failure of the effort to roll back the methane rule is a small but significant victory for environmentalists in the Trump era, as the president has pushed aggressively to dismantle most of his predecessor’s environmental legacy.

The methane rule was one of a suite of environmental regulations put in place by Obama as he sought to use his executive authority to tackle climate change across the economy. While methane vented from oil and gas wells accounts for only a small portion of the nation’s greenhouse gas pollution, environmental advocates urged Obama to tackle the emissions because methane is more than 25 times more potent than carbon dioxide in trapping heat in the earth’s atmosphere.

The failure to repeal the methane rule, which required a simple majority of 51 votes to pass, comes as the Senate nears the end of its window to use the Congressional Review Act to undo major regulations. Under that law, which was used successfully only once before this year, Congress can vote to erase new executive-branch regulations within 60 legislative days of their completion. Since Trump’s inauguration, the White House has successfully pushed Congress to roll back more than a dozen Obama-era rules, including four other environmental regulations.

Under Trump, lawmakers have used the Congressional Review Act to roll back several Obama administration environmental regulations, such as ones that would have:

■ Limited the way coal mining companies could dump debris into streams after blowing up mountaintops to gain access to coal deposits.

■ Required oil, gas, and mining companies to disclose payments made to foreign governments in exchange for access to drilling or mining rights.