Gwen Stefani debuts her son Apollo for the first time Credit: Uri Schanker/GC Images

Those cheeks! Gwen Stefani debuted her 6-month-old son Apollo for the first time on Thursday, Sept. 4. The cherubic cutie joined his songstress mom at the 2014 US Open in New York City.

Wearing a leather jacket and grinning from ear to ear, the blonde Voice coach, 44, held her adorable tot in her arms while watching a match between Roger Federer of Switzerland and Gael Monfils of France.

At one point during the match, the mom of three took out her iPhone to FaceTime with Apollo's big brothers Kingston, 8, and Zuma, 6, whom Stefani shares with husband of 12 years Gavin Rossdale.

During an interview with Seth Meyers on Wednesday, Sept. 3, the "Hollaback Girl" singer joked that it was Kingston who wished Apollo into the universe.

"[Kingston] asked me, ‘Mom, are you going to have a baby? I want you to have a baby,’” she told the talk show host. "I was like, 'It's over. We’re not having any more. This is our family.' [But,] Kingston … has a direct link to God, basically," she laughed. "[He started to pray,] 'Dear God, please let my mom have a baby. Please, God! Please let my mom have a baby' … I swear to you, he prayed every single night," Stefani said. "And four weeks later, I was pregnant!"