Complex sentence: It reached the top position on November 21,2010, was succeeded by Rihanna's "Only Girl (In the World)" on the following week, but returned to number one on December 5,2010 for an additional week.
Split into simpler sentences: It reached the top position on November 21,2010, but was succeeded by Rihanna's "Only Girl (In the World)" on the following week. However, "Sun Is Up" returned to number-one on December 5,2010 for an additional week.