Ciara is out and American Idol winner Jordin Sparks is in as opener for Britney Spears' opener during the second leg of her North American "Circus" tour.

She joins One Call, Girlicious Kristinia DeBarge, the other supporting acts, who were previously announced.

According to Rap-Up.com, a spokesperson for Ciara said she's no longer on the tour, though she opened a few dates in the U.K. No reason was specified.

In a press release on Britney's site, Sparks is quoted as saying "Britney's show is incredible and for me to be a part of it is a great opportunity."

Meanwhile, some of the only officially released footage from Britney's Circus tour has hit Yahoo!, and features the bat-shit crazy lengthy opening sequence to the performance. And some botchy lip-syncing on the pop princess' part.

Dates and video below.

August 20  Hamilton, ON             Copps Coliseum + @ ^
August 21  Ottawa, ON                Scotiabank Place + @ ^
August 24  New York, NY           Madison Square Garden * + ^
August 25  New York, NY           Madison Square Garden * + ^
August 26  New York, NY          Madison Square Garden * + ^
August 29  Boston, MA                TD Garden * + ^
August 30  Philadelphia, PA         Wachovia Center + ^
September 1   Orlando, FL                 Amway Arena * +
September 2   Miami, FL                    American Airlines Arena * +
September 4   Atlanta, GA                 Philips Arena * +
September 5   Greensboro, NC           Greensboro Coliseum * +
September 8   Detroit, MI                   The Palace of Auburn Hills * +
September 9   Chicago, IL                  Allstate Arena * +
September 11  Des Moines, IA            Wells Fargo Arena * +
September 12  Grand Forks, ND          Alerus Center * +
September 15  Tulsa, OK                     BOK Center * +
September 16  Houston, TX                Toyota Center * +
September 18  Dallas, TX                    American Airlines Center * +
September 19  Bossier City, LA          CenturyTel Center +
September 21  El Paso, TX                  Don Haskins Center * +
September 23  Los Angeles, CA         STAPLES Center * +
September 24  San Diego, CA            San Diego Sports Arena * +
September 26  Las Vegas, NV            Mandalay Bay Events Center * +
September 27  Las Vegas, NV           Mandalay Bay Events Center * +

 *with special guest Jordin Sparks
+ with special guest Kristinia DeBarge
@ with special guest Girlicious
^ with special guest One Call