WASHINGTON (AP) — Democrat Pete Buttigieg said Monday that he took in $24.8 million during the second fundraising quarter, more than triple what the South Bend, Indiana, mayor raised during the first three months of the year for his surprise hit presidential campaign.

Buttigieg was the first White House contender to announce his fundraising numbers for the quarter, which ended at midnight. His haul amounts to a show of force at a critical early juncture in the race where fundraising figures, and the number of people giving to a campaign, aren’t just indicators of viability but criteria for qualifying for the debate stage in September.

“Pete has proved why he is a top-tier candidate for the nomination,” campaign manager Mike Schmuhl wrote in an email to supporters. “From town halls on MSNBC, CNN, and FOX News to last week’s debate, he’s shown the country what I’ve known for a long time: Pete is the best person to bring a new generation of leadership to Washington.”

Buttigieg, 37, surprised many people with a first-quarter haul of roughly $7 million that topped many of his better-known rivals and helped place him in the top tier of a crowded 2020 field that has drawn more than 20 contenders. His latest numbers further cement him as a leading candidate and are sure to draw notice from rival campaigns, many of whom have struggled to raise money.

The $24.8 million sum tops the $18 million raised last quarter by Bernie Sanders, who led the Democratic field in fundraising during that period.

More importantly, Buttigieg is doing well enough in public opinion polls and has received contributions from more than 400,000 people, which secured his spot in the September debates.

Democratic National Committee requires participants to hit 2% in multiple polls and 130,000 individual donors. Though many campaigns are worried, DNC Chairman Tom Perez has resisted pressure to relax the requirements.

Currently, the only other locks for the fall debates are former Vice President Joe Biden, Sanders, Massachusetts Sen. Elizabeth Warren and California Sen. Kamala Harris.

Buttigieg’s campaign says he has $22.6 million cash on hand and received money from donors from all 50 states, as well as U.S. territories, with an average contribution of about $47.

Associated Press writer Sara Burnett contributed from Chicago.