Justin Bieber was back in business and, according to the sounds emanating from thousands of shrieking fans, none the worse for wear barely 24 hours after collapsing onstage.The 19-year-old heartthrob was apparently feeling well enough Friday night to pull off his fourth and final show at London's O2 Arena, clad once again in his all-white blazer and pants with gold gloves and gold-accented hightops.

"still a little short of [breath] tonight but was an incredible show," Bieber tweeted afterward. "London fans go hard! 4 SOLD OUT O2 shows in a row!! #BLESSED."
Rough 24 hours: Watch Justin Bieber's run-in with the paparazzi in London this morning
"too many blessings to allow the stress in," he continued. "the press made things look nuts but really I have enjoyed London. The fans are incredible."
Bieber concluded: "so while I have seen some crazy stuff it is all smiles. Im gonna get some rest and keep doing what i love. Entertain all of u. thanks."
And the fans would certainly like to thank him back, both the ones who attended Thursday's show and got a major scare when their hero crumpled to the ground mid-song and needed a break for oxygen backstage, and those whom he showed up for tonight.

Justin Bieber to resume tour after scare

The 19-year-old singer took a 20-minute break during Thursday's show at the O2 Arena in London as his manager told the crowd he was "light of breath".
He later had a check-up in hospital but is expected to perform on Friday.
His eventful week continued earlier on Friday when he was filmed clashing with a photographer.
The altercation took place as Bieber exited a Park Lane premises into a waiting car.
"Let the paps get the best to me," he tweeted after the incident.
"Sometimes when people r shoving cameras in your face all day and yelling the worst thing possible at u... well I'm human."
Friday night's show will be the final concert of a four-night run at the O2 Arena.
The singer moves on to Portugal and Spain next week and has 63 live dates remaining on his world tour, which lasts until August.
'Gettin better' After Thursday's show, the heartthrob wrote on Twitter that he was "getting better".
He continued: "thanks for everyone pulling me thru tonight. best fans in the world. figuring out what happened. thanks for the love."
He also sent a picture of himself, via Instagram, lying in what appeared to be a hospital bed with the caption "gettin' better".
His spokeswoman Melissa Victor said: "He fainted and took a 20-minute reprieve and was given oxygen."
In a video posted by a fan on YouTube, Bieber's manager Scooter Braun was seen on stage explaining why the show had come to a temporary halt.
He told fans: "Justin got very light of breath, the whole show he's been complaining. He's backstage with the EMTs [emergency medical technicians] and the doctor.
"They're telling him they want him to go and see somebody and find out what's going on with his lungs, he's just told me that in five minutes, if it's OK with you guys, he's going to come out and finish the show.
"So he might not be jumping around as much and everything else, you guys need to be patient with us, we're not trying to be disrespectful, we're not trying to get you guys home late, we're truly trying to put on a show for the people who love him."
Bieber did return to complete the show before being examined by medical staff.
The singer has had a whirlwind fortnight in the UK, being photographed in several nightclubs, in between his concerts in Manchester, Liverpool, Birmingham, Nottingham and London.
He was criticised for keeping fans waiting after coming on stage late for Monday's performance in London.