I too am a Duke fan and will happily weigh in.
Marche Moderne is a great choice, probably my favorite in all of OC. It has a small bar where you can eat, if you dislike dining at a table alone.
Closer to the airport is a very good upscale Italian restaurant, Il Barone. Beautiful fish specials and made-in-house pasta. I strongly recommend it, and if you are without a car, you can easily walk there from the airport-adjacent hotels.
Anqi is another good choice for food you aren't likely to get everywhere, also near Marche Moderne at South Coast Plaza.
And by the way, if you need a basic sports bar to watch opening night of March Madness, near the airport is the Classic Q. Not exactly chow-worthy food (although the burgers aren't bad), that might trump other options, although duke doesn't play until Friday.
What do you want to eat?
Marche Moderne is French and arguably the beast restaurant in OC, but maybe you already have a good French place back home.
There are a few excellent sushi bars local, and that may be something you are not likely to get. In all of these places, I would order the Omakase (chef's choice) and let them know if you have any restrictions (ie. I don't eat shellfish) and that you are adventurous:
San Shi Go (My favorite)
There are also excellent ethnic options in and around OC. Some of my favorites are:
Merhaba - Ethiopian (Really Eritrian, but I don't know the difference)
Thai Nakorn - Thai
Shin Sen Gumi - Japanese Yakatori (the Ramen place maps here, but it is right next door)
Honda-ya - Japanese pub food (small plates)
Trieu Chau - Hole in wall Vietnamese
Brodard Chateau - upscale Vietnamese with French Influence
Shin Sen Gumi Hakata Ramen
18315 Brookhurst St, Fountain Valley, CA 92708
Thai Nakorn Restaurant
12532 Garden Grove Blvd, Garden Grove, CA 92843
590 W 19th St, Costa Mesa, CA 92627
9039 Garfield Ave, Fountain Valley, CA
New Trieu Chau Restaurant
9902 Westminster Ave, Garden Grove, CA 92844
9100 Trask Ave Garden, Grove, CA
Honda Ya Japanese Restaurant
556 El Camino Real, Tustin, CA 92780
E A Merhaba Shop & Coffee
2801 W Ball Rd # 5, Anaheim, CA
San Shi Go Sushi and Asian Cuisine
205 Main St, Newport Beach, CA 92661
3333 Bristol Street, Suite 3001, Costa Mesa, CA 92626