Britain's men levelled the three-match series with Argentina thanks to a 2-1 win at Bisham Abbey in which all three goals came in the final quarter.
Argentina, who won the opening match 3-2 on Monday, hit the post in the first half and took the lead through Gonzalo Peillat's drag flick low into the net.
But Tom Carson levelled by firing in a rebound and only seconds were left when Ian Sloan struck the winner with a powerful drag flick, his first GB goal.
The deciding match is played on Friday.
The series is part of Britain's preparations for the World League Final, which starts on 27 November in India.
Coach Bobby Crutchley made six changes to his side, including giving Simon Mantell his first appearance in a GB shirt in almost a year after recovering from concussion.
"We had an inexperienced team compared with Monday, we lost a great deal of caps with the players we left out, but that's the challenge I was setting the group," he said. "I wanted to see how people step up to the mark, which these players did very well.
"The depth of the squad is something we've worked on for a while. It's great we've improved it to some degree but there is still a way to go. We have to know that if we lose any of our experienced players we can still cope."