Team GB were held by Ireland to a 2-2 draw in their second pool game in the World League semi-final in Antwerp.
GB are second in their pool, following a 2-2 opening result against Belgium, with the tournament's top three sides qualifying for the Rio 2016 Olympics.
Both Britain's goals came in the opening 10 minutes, through captain Barry Middleton and Chris Griffiths.
Kyle Good scored for Ireland after 21 minutes before John Jackson's goal ensured both sides left with a point.
Middleton said: "It's frustrating because in both games we have been ahead and they have come back and got draws.
"We just needed to do a few things a little better when they had to come out and press us.
"We didn't quite do it as well as we wanted to and we probably weren't quite as good as we can be."
Ireland coach Craig Fulton said "Overall we're happy with the result. We were a bit nervous in the first quarter but settled in the second quarter and got on the scoreboard.
"The second half was pleasing, we created some good phases of play which was more like us. We're looking forward to the next game against Malaysia (on Thursday)."
The match saw GB's Mark Gleghorne come up against brother Paul, who was playing for Ireland.
Hosts Belgium could leapfrog GB in Pool B with a win over the tournament's lowest-ranked side, China, on Tuesday evening.
The top four teams in each pool will qualify for the quarter-finals, starting on Wednesday, 1 July.
Great Britain face China in their next match on Thursday.