South Bend, Ind., Mayor Pete Buttigieg on Monday announced his Democratic presidential campaign raised more than $7 million in the first quarter of 2019, a figure likely to propel the largely lesser-known candidate to the upper ranks of his party's primary field.

“This is just a preliminary analysis, but our team’s initial report shows we raised over $7 million dollars in Q1 of this year,” Buttigieg tweeted. “We (you) are out-performing expectations at every turn. I'll have a more complete analysis later, but until then: a big thank you to all our supporters.”

[Opinion: Pete Buttigieg is the 2020 Democrat who could work with Republicans]

Buttigieg is running in primary field of more than a dozen other Democratic candidates, with more likely to join the fray in the coming weeks. Buttigieg began the race as an asterisk in name recognition, but his heavy interview schedule and prolific public events have bolstered his candidacy.

Sunday marked the end of the first-quarter fundraising period, and public reports are due by April 15. Rival Democratic candidates have already boasted of their fundraising prowess.

Former Texas Rep. Beto O’Rourke, who gained national attention when he came within striking distance of defeating Republican Sen. Ted Cruz in 2018, recently said his campaign raised more than $6 million during his first 24 hours of candidacy in mid-March.

Sen. Bernie Sanders of Vermont, an independent in Congress seeking the Democratic nod for the second straight cycle, has said his campaign raised $3.3 million in the first 12 hours after announcing.

[Read more: Beto O'Rourke soars, Pete Buttigieg climbing: Poll]