If it's a quality one, yes. I ran a 7970 overclocked with an overclocked i5-4670K on a CX430, 2x Samsung 830 SSD's and a blu ray drive. 5 120MM fans. No issues.
You'll be fine with a good name brand/well built unit. I have a Mini-ITX gaming rig hooked up to my tv. It's equipped with a 450W Silverstone SFX power supply. Inside is an i5-3470, GTX 670, 3.5" HDD, SSD, BD-burner, and cooled using a 140mm Air Penetrator fan and a Corsair H60i AIO cooler. No problems/instability from power that i've noticed.