Ashley Jackson's penalty corner secured a draw for Great Britain in the first Test of a two-game series against Argentina.
The hosts dominated at Bisham Abbey, but went behind on 54 minutes through Lucas Vila's strike from a penalty corner rebound.
But with seconds remaining, Jackson levelled with a precise flick.
Britain's coach Bobby Crutchley said: "It's frustrating we didn't win the game as we had more chances."
Crutchley gave debuts to Beeston's David Ames and Wimbledon's Ian Sloan, and the two teams will meet again on Friday at 11am at Bisham Abbey.
Ames and Sloan both previously played for Ireland.