Though she canceled three performances last week, Houston, 46, told fans at Birmingham's LG Arena that she felt "pretty good" during her first concert in the U.K. in over a decade.
The singer looked and sounded pretty good too, starting off with songs from her new album I Look to You. Despite a technical hitch with her microphone, she confidently strutted around the stage in fitted white pants, a long flowing white blouse and a silver jacket. Thanking the crowd for their love, support and loyalty, Houston even paused to sign an autograph for a fan between songs.
But things soon took a turn for the worse.
When Houston left the stage for a lengthy wardrobe change, the audience became restless, even booing the singer as her brother, Gary Houston, tried to keep the crowd of 15,000 entertained with a solo performance of one of his sister's tracks, and her three backup singers performed their own version of the Houston hit "I'm Every Woman."
About 15 minutes later, the star re-emerged and addressed her absence. "Thank you for being understanding, letting me dry off and change my clothes," she said, adding, "I heard you get mad ... but I understand, I'm here now."
But that wasn't enough for some fans and critics, who noted that she appeared "tired" and "erratic." She struggled to hit the high notes in many of her signature anthems such as "I Wanna Dance with Somebody" and "All at Once," appearing breathless onstage and asking arena staff, "If there is any [air conditioning] in the house, please turn it off. I just got over a really bad cold ... Please make it quick!"
The singer continued to battle through her set and concluded with a husky version of her signature hit, "I Will Always Love You." Appearing to have lost her voice altogether, she gestured the sentiment to her fans, clutching her chest and blowing kisses as she took her final bow. "Just heard a clip of Whitney Houston from her show last night singing 'I Will Always Love You," wrote one viewer on You Tube. "Get your money back!"
Still, The Guardian praised Houston's vocals and declared "she's definitely back, while the U.K's Times noted that her "old magic" was back.
Houston continues her tour in Nottingham, England, on Wednesday night and heads to Ireland on Saturday.