Gwen Stefani's performance of "Used to Love You" at the 2015 American Music Awards in Los Angeles Sunday night was the best of the night, according to her rumored boyfriend Blake Shelton. Reuters

Blake Shelton didn’t attend the 2015 American Music Awards in Los Angeles Sunday night, but that doesn’t mean he wasn’t cheering on his rumored girlfriend. The country singer made sure to compliment his “Voice” co-star and speculated love interest Gwen Stefani’s AMA performance online during the live show.

As reported by People, Shelton, 39, made it clear to one Twitter follower that he was a fan of Stefani’s performance of her new single “Used to Love You.” When one fan tweeted to Shelton that the former No Doubt singer’s performance was “the best of the show,” he responded, saying, “Agreed…”

Ahead of Stefani’s performance, Shelton also tweeted “prepare for greatness,” though it’s unclear whom he was referring to, as the AMAs saw dozens of musicians hit the stage.

Stefani, 46, hit the AMAs red carpet and stage solo, despite her speculated new romance with Shelton. Her souful song was inspired by her recent split from husband Gavin Rossdale. Despite singing her emotional ballad at the awards ceremony, it doesn’t appear Stefani is heartbroken anymore. The songstress has been said to be dating Shelton, who split from wife Miranda Lambert in September, since October.

Stefani last opened up about Shelton during an appearance on “The Ellen DeGeneres Show” Nov. 20. During her interview, Stefani said she wasn’t aware of Shelton before co-starring alongside him on NBC’s “The Voice.” She also shared that she's a fan of his impressive knowledge of music.

“He knows every single '80s song. He literally is a musical jukebox. He knows everything about music,” Stefani said.

When asked by DeGeneres if the country crooner is a “good kisser,” Stefani only blushed.

Watch Stefani talk about Shelton on “Ellen” below:

While Stefani isn’t sharing every detail about her life since splitting from Rossdale, she did confirm to DeGeneres that she’s happy. “I am in a good place. I’m having a lot of fun,” she said. “It’s like a whole new life, a whole new chapter."