There were a million reasons to go to bed early on Sunday night, but one of those wasn't Lady Gaga. Just before midnight, the singer popped up inside Las Vegas' NoMad Restaurant to perform a surprise six-song set.

Social media video shows Gaga belting out "I Can't Give You Anything But Love" with her trumpeter Brian Newman standing next to her.

The surprise drop-in came during Newman's "After Dark" late-night lounge series at NoMad following her Jazz & Piano show at Park MGM in Las Vegas.

"How's everybody doing tonight," Gaga said as she shimmied up to the microphone, according to "Well, I sang for two and half hours so this s--- we are about to do is f---ing irresponsible."

During the middle of her fifth song, Gaga, drained from her previous concert, asked that a chair to be brought up to the tiny stage.

"This is what happens after two and half hours of performing and five glasses of whiskey," she joked to the audience of 100.

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As she finished around 1:30 a.m., Gaga and Newman got multiple standing ovations.

While it was certainly a draining evening physically for Gaga, things also got sentimental for her.

Earlier in the evening, during her Jazz & Piano residency show, Gaga briefly addressed her split from ex-fiancé Christian Carino before singing "Someone to Watch Over Me."

"Last time I sang this song, I had a ring on my finger," she told the sold-out crowd, "so it'll be different this time."

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The former couple first sparked split rumors in February when Gaga attended the 2019 Grammy Awards without Christian or her engagement ring. The split was later confirmed.

"Gaga has been in such a focus on her career right now and has not even had time to address what has been happening between her and Christian, emotionally," a source told Us Weekly at the time. "She has been telling those around her, 'Let's stay focused.'"