"I Knew You Were Trouble" also became her second number-one song there, following "Love Story," which reached number one for one week on the week ending February 28, 2009.It also became her first number-one on the "Billboard" Adult Pop Songs chart, where she'd risen as high as number two with "You Belong with Me" and her second number-one song in "Billboard" Hot 100 Airplay, where it peaked at number one for four weeks.