at the top of game
at the top of (one's) game
At one's best or most skillful. I can't believe I got the hardest question right. I'm really at the top of my game today! I think their quarterback is at the top of his game this year—I doubt he'll be able to replicate these stellar stats next season.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
at the top of one's game
Fig. good and as good as one is likely to get. (Usually of sports.) I guess I was at the top of my game last year. This year, I stink.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.