DIANA ROSS WEEK ''A lot of people maybe think this is a two-girl, Lakisha-Melinda race...Tonight, with that, you just made it a three-girl race,'' predicted Randy after Jordin's performance of ''If We Hold on Together.'' Though Ms. Ross advised her to connect more with the audience, she recognized that Jordin's spark would get her far: ''To me, she has star quality...You see that glitter and the shine in her eyes.''