off to the races

(idiomatic) In or into a process of energetic engagement in some activity; in or into a phase of conspicuously increasing satisfaction or success.

Example: 1964 July 10, "Industry: Top Money," Time:
  Last week the magazine's tenth annual rating of the nation's leading corporations showed that American business really went off to the races in 1963.
1994 June 3, Leonard Pitts Jr., "Movies," Milwaukee Journal, p. 21E (retrieved 26 Aug 2012):
  48 Hours . . . was followed by hits such as Trading Places, Beverly Hills Cop and Raw. Eddie Murphy's career was off to the races.
2004 Jan. 19, Janet Maslin, "When the High and Mighty Tumble, Duck and Cover" (Book review of The Best Awful by Carrie Fisher), New York Times (retrieved 26 Aug 2012):
  And with that, this tartly funny book is off to the races, inviting readers to tag along on a wild manic ride.