Like some short tennis matches

2SET

Think of how a quick victory might be scored in tennis when only two are needed instead of the usual three.

The clue refers to tennis matches that end quickly, often in just two sets instead of the usual best-of-three or best-of-five. "2SET" is shorthand for a match won in two sets, like "6-3, 6-2," where no third set is needed. The answer plays on the idea of "short" meaning both brief in duration and limited in sets. It’s a straightforward definition with no hidden wordplay—just tennis terminology.