'TOP CHEF DUELS': Los Angeles restaurateur Antonia Lofaso and DC's Mike Isabella challenge one another on the latest episode of 'Top Chef Duels.' (Nicole Wilder/Bravo)

The top six finalists team with all-stars to perform on “So You Think You Can Dance” (Fox at 8 p.m.), with Christina Applegate playing guest judge and a performance from Rixton.

“Who Do You Think You Are?” (TLC at 9) welcomes Kelsey Grammer and unearths a dark past complete with demons and a great migration.

FINALE WATCH: The recently renewed “Suits” (USA at 9) closes its fourth season with Harvey and Jessica protecting the firm from competitors and Louis trying to balance his personal and professional affairs.

Two back-to-back episodes of “Extant” (CBS at 9 and 10) have Molly in panic after coming to the conclusion that the agency must have her baby and plotting with Kern and Kryger to help save it.

When a maid from El Salvador is shot, Cat, Leo and Frankie discover she is actually a former cop from Venezuela who’s in Brooklyn to avenge the death of her parents on “Taxi Brooklyn” (NBC at 10).

D.C. restaurateur Mike Isabella and restaurateur Antonia Lofaso from Los Angeles challenge each other on “Top Chef Duels” (Bravo at 10).

Sonya uncovers the truth behind Lisa’s death on “The Bridge” (FX at 10), while Frye and Adriana stumble upon something dangerous that puts their loved ones at risk.

SERIES PREMIERE: The reality series “Epic Ink” (A&E at 10:30) is, yet again, about tattoo artists who work in a shop in Oregon that specializes in pop-culture related tattoos. You want Boba Fett or the Smurfs on your chest? These are your people.

SERIES PREMIERE: The six-part British drama series “Happy Valley” (Netflix) stars Sarah Lancashire (“Last Tango in Halifax”) as a “hard-working, no-nonsense police sergeant” who finds herself in over her head while investigating a staged kidnapping that goes out of control.

Actors Jared Leto and Amy Brenneman are on “The Tonight Show Starring Jimmy Fallon” (NBC at 11:35), along with a performance from Leto’s band, Thirty Seconds To Mars, and Tom Bailey.

Comedian Kathy Griffin and documentarian Ken Burns come to the “Late Show With David Letterman” (CBS at 11:35), with music from indie pop musician Jeremy Messersmith.

Actors Ted Danson and Eva Green stop by on a repeat “Jimmy Kimmel Live” (ABC at 11:35), with musical guest Jake Owen.

Rachel Lubitz