Gwen Stefani and baby Apollo spotted at US Open

Gwen Stefani and baby Apollo took in the U.S. Open on Thursday.
The 44-year-old singer and her son cheered on Roger Federer of Switzerland in his five-set match against Gael Monfils of France. Stefani got silly when she was spotted on the jumbotron, and her enthusiasm reflected the thrilling tennis showdown. Monfils won the first two matches and had match points in the fourth, but ultimately succumbed to Federer in the fifth set.
Stefani took the time to video chat with sons Kingston and Zuma during the event. The singer appeared on Late Night with Seth Meyers on Wednesday, and told the host Kingston's prayers helped her to have baby Apollo.
"Kingston ... has a direct link to God, basically," she said. "[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, and four weeks later, I was pregnant."
Stefani will debut as a coach on NBC reality competition The Voice on September 22. The singer recruited husband Gavin Rossdale to mentor her team on the new season.