Last week’s premiere of the original animated series “Star vs. the Forces of Evil” has become the most-watched animated series debut in Disney XD’s 15-year history.

Monday’s 8 p.m. premiere of “Star vs. the Forces of Evil” averaged 1.2 million viewers within the first three days of its premiere telecast, according to Nielsen Live+3 estimates. “Star vs. the Forces of Evil” joins October’s launch of “Star Wars Rebels” (1.1 million) as Disney XD’s top two animated series launches on record in total viewers.

Among all series on the network, it ranks second to date behind only the live-action original series “Lab Rats” in February 2012. It’s also Disney XD’s No. 2-rated animated series debut in kids 2-11 (582,000) and kids 6-11 (435,000) and the No. 3-rated animated series premiere in boys 6-11 (233,000).

In its timeslot, “Star” ranked second among kids 6-11, behind only Disney Channel’s “Bad Hair Day.” A second episode following at 8:30 p.m. retained 93% of the premiere’s kids 6-11 audience (406,000 vs. 435,000) and 94% of its boys 6-11 audience (219,000 vs. 233,000).

“Star vs. the Forces of Evil” is a production of Disney Television Animation, created and exec produced by 2009 CalArts graduate Daron Nefcy. It follows teen princess Star Butterfly, who receives an all-powerful magic wand for her 14th birthday and is sent by her Royal Parents to live with the Diaz family on Earth, bringing along her own unique interdimensional style to her new home.

In other Live+3 ratings results for last week, TLC scored a strong 4.3 million viewers on Tuesday for its “19 Kids & Counting” special on the wedding of Jessa Duggar and Ben Seewald. The two-hour telecast was No. 1 among all television programs airing in the 8-10 p.m. window on Tuesday in women 18-49, women 18-34 and adults 18-34, and it was cable’s most-watched Tuesday program overall.