Britain's men are on the brink of qualifying for the Rio Olympics after a 2-1 win over Pakistan set up a World League semi-final against Australia.
Chris Griffiths put GB ahead before Alastair Brogdon deflected Ashley Jackson's effort home to make it 2-0.
Muhammad Bhutta pulled one back but GB held on to book a match with the world's top-ranked side despite having Henry Weir sin-binned for five minutes.
A top-three finish in Belgium would secure a place at next year's Olympics.
But Britain's qualification is likely to be confirmed in October whatever their result against Australia on Friday as fellow semi-finalists India will play in Rio as Asian champions.
GB overcame pitchside temperatures reaching 39C in Antwerp.
"The first half was really good and if we had got another goal we would probably have got more," said captain Barry Middleton.
"I thought we defended quite well and it felt quite comfortable."
The final and the third-place play-off both take place on Sunday.