Whitney Houston kicked off the British leg of her tour late on Tuesday after cancelling a string of gigs due to illness, but some critics were less than impressed with her performance.
"Houston, we still have a problem" was the conclusion of the bestselling tabloid the Sun on Wednesday in a brief review of the 46-year-old's concert in Birmingham.
"It was not the performance fans were hoping for."
The BBC's Colin Paterson said there were "great moments" during the show, highlighting "It's Not Right, But It's OK" and "How Will I Know."
"But 'I Will Always Love You' will live long in the memory, and not for the right reasons," he wrote, adding that Houston appeared short of breath throughout the show which she blamed on a cold and the air conditioning.
"Those going to see Whitney tonight in Nottingham will hope things are alright. If they are even OK, it will be an improvement on last night," he wrote.
Alison Dayani of the Birmingham Post also said the singer appeared breathless, and broke up the set with water breaks and chats with the audience apparently to give her time to recover.
"The straw that finally broke the crowd's back" came as Houston took a 15 minute break, and when a video of "One Moment In Time" was played there were boos in the arena, she added.
The Independent's Elisa Bray was more positive, saying that Houston, hospitalized in Paris this month after suffering a respiratory infection, had learned to pace her set better than in Australia where she was panned by fans and critics.
"If tonight was the first to attempt to recreate her early zest, she did not quite make it. But it's still an impressive voice -- and you feel lucky to hear Houston live," Bray said.
"Tonight was definitely a spectacle -- and for the most part in a good way."
Houston, one of the top-selling female artists of all time, launched a comeback last year after battling drug addiction and released her first studio album in seven years which topped the U.S. and other charts.
She has dismissed as "ridiculous" recent speculation in some media that she had relapsed into drug use.
"At this point, I just don't respond," she told People magazine. "I don't even read it."
The singer is due to travel to Nottingham on Wednesday before moving to Dublin, Ireland, for three dates, Newcastle and London's O2 Arena later this month. She then goes to Europe, including Italy, Switzerland and Germany.
(Reporting by Mike Collett-White, editing by Paul Casciato)