The No Doubt member, who sported a black leather jacket and full makeup, held her adorable six-month-old son who wore a colourful jacket, black pants and socks, reported Ace Showbiz.
During the game between Switzerland's Roger Federer and Gael Monfils of France, the 'Voice' coach was seen having FaceTime session with her other sons who were at home.
The 44-year-old singer later also had a chance to take a selfie together with Federer. "Omg!! #goroger #usopen2014 #urmagic gx," she captioned the snap.