Jennifer Hudson 'Emotional' At 'Voice' Taping Amid Custody Battle

The top 12 contestants competed against each other during last night's live taping of NBC's The Voice, but all eyes were on coach Jennifer Hudson in her first appearance since her nasty separation and custody battle exploded last week.

RadarOnline.com has exclusively learned from an insider that Hudson, 36 – who recently filed a protective order against ex-fiance David Otunga, 37 – was "extremely emotional" on set.

However, "she did not make any type of scene," the source said. "She arrived on time, did the show and then left right after it was wrapped."

And after the Oscar-winner was bashed for her harsh criticism and diva antics all season, she was on her best behavior during last night's filming.

"It was like she was a different person, and actually showed compassion to contestants," the insider said.

And it showed during her commentary, as Hudson — whose contestant, Noah Mac, is a frontrunner to win this season — went out of her way to tell a contestant from rival Miley Cyrus's team : "Tonight you represented the power of music and what it can do. You did what this show is about. You showed us you have a voice."

As previously reported by RadarOnline.com, the Chicago-based Hudson's role on the hit show could be a disadvantage in her battle with Otunga over David Jr., 8.

Tracy M. Rizzo, an attorney for Otunga, told RadarOnline.com: "Jennifer was doing The Voice overseas, and is now doing The Voice in L.A...She is everywhere but at home with her son...He is definitely in better hands with his father."

Hudson filed a petition for emergency order of protection in Illinois' Cook County Court on November 16, accusing Otunga of "increasingly aggressive, threatening and harassing behavior." She gained temporary custody of their son.