DOVER, Delaware -- In only its second year, the Firefly Festival scored big in 2013, landing veteran acts the Red Hot Chili Peppers and Tom Petty -- but it was Sunday's sets from relative newcomers Vampire Weekend and Foster the People that stole the show.

After a day of soaking rain showers, soggy festivalgoers happily danced in the mud to Vampire Weekend's sunny hits "Cousins," "Oxford Comma," "Holiday" and fan favorite "Diplomat's Son."

"We feel at home," singer Ezra Koenig told the crowd.

Vampire Weekend -- whose third album, [article id="1707856"]Modern Vampires of the City[/article], debuted at #1 last month -- have scheduled a worldwide run of festivals this year. They are headed to the U.K. for Glastonbury this week and will swing through Europe and Asia before returning to the States in August for [article id="1704695"]Lollapalooza[/article], [article id="1705757"]Outside Lands[/article] and [article id="1706907"]Austin City Limits[/article].

As Foster the People closed out Firefly on Sunday night, you'd never guess the band has only been performing live since 2010 and has just one album under its belt.

Their huge stage show -- featuring a horn section, masked dancers and backup singers -- highlighted the feel-good dance-party vibe of "Don't Stop (Color on the Walls)," "Helena Beat" and "Call It What You Want."

A raved-up take on their breakthrough hit "Pumped Up Kicks" ended the festival with a blast, as singer Mark Foster sprinted across the stage banging a cowbell.

Passion Pit, Zedd and Haim also performed Sunday.

[article id="1709451"]Kendrick Lamar[/article] called his Saturday afternoon set "a beautiful thing," telling MTV News, "It was a crazy crowd."

Earlier in the weekend, Schoolboy Q filled in for [article id="1709429"]Earl Sweatshirt[/article], who indicated on Twitter that he's still suffering from the case of pneumonia that kept him away from [article id="1709020"]Bonnaroo[/article] the previous weekend.

The Lumineers were also sidelined by an illness in the band; they were replaced by Ben Harper.

The 2013 Firefly Festival also featured Yeah Yeah Yeahs, MGMT, Public Enemy and Twenty-One Pilots.

Did you go to Firefly? Share your reviews in the comments below!