The country star took a break from her tour to celebrate a night of music Matt Winkelmeyer/Getty Kelsea Ballerini came to slay ... but a major cutout in the middle that showed off her toned abs. The ...

The star's sizzling dress thrilled fans, with many raving about her toned abs ... where he plays John B, writing, 'Kelsea Ballerini’s abs and face and everything wtf i die John B you lucky ...

Kelsea Ballerini came to Phoenix in support of "Patterns." She sang "Penthouse," "Miss Me More," "Love Me Like You Mean It" ...

Ballerini dazzled in a black, sweetheart-neckline dress featuring a cutout that showed off her toned abs. The sequined gown matched her diamond-encrusted heels.

Kelsea Ballerini's ... to set the tone with two songs from her latest album, "Patterns," on which her only co-writers were other women, Ballerini took a moment to address the crowd.

Kelsea Ballerini came to slay ... but a major cutout in the middle that showed off her toned abs. The number also featured a daring thigh-high slit that showed off her mesh ankle-strap heels.

Kelsea Ballerini came to slay. The "Cowboys Cry Too" singer was ... but a major cutout in the middle that showed off her toned abs. The number also featured a daring thigh-high slit that showed off ...