front runner
The person or thing most likely to be awarded something. I hear that movie is the front runner for the Best Picture Oscar. Amanda's the front runner for the position—she's overqualified, honestly, and has a great attitude.
front-runner
the person or thing thought most likely to win or succeed. The press found out some juicy secrets about the front-runner and made them all public. Who is the front-runner in the race to be governor?