noun
top two; two strongest
Refers to the two leading or most powerful entities in a group, often used in sports, competitions, or rankings. The cross-reference to 強 (sense 2) suggests a connection to the concept of 'strength' or 'power'.
See also: 強
今シーズンは二強が抜けている。
This season, the top two are pulling ahead.
二強の争いになりそうだ。
It looks like it will be a battle between the top two.