Seven points currently separate the second-placed Northern Irish and the Czechs with three games to go, meaning Karel Jarolim’s side have to win or their hosts will be guaranteed at least a runners-up berth.
O’Neill wants his players to kill off that morsel of hope and gain a mental upper hand that he believes will be pivotal in front of a buoyant Belfast crowd.
“The focus is on ourselves, we know we’re going to have to play extremely well and produce a big performance,” O’Neill admitted.
“But it is one of those games where the psychological side of the game will be huge.
“It’s going to be a difficult game for them if they go behind, to continue to believe.
“We have to try and make that (happen) and try and take whatever hope they have away from them early in the game.”
Czech Republic were beaten 2-1 by group leaders Germany in Prague on Friday but had one eye on their following fixture three days later when they made six changes.
Their loss to the Germans means the onus is on them to become the first visiting side to win a competitive game at Windsor Park since Portugal in 2013, and O’Neill is banking on those in the terraces being an X-factor for his team.
“The crowd will play a massive part because it gives you energy when you don’t have it,” he noted.
“There will be times during the game we’ll be under pressure, I’ve no doubt about it. The Czech Republic have to come and win the game, it’s as simple as that.
“It’s their last throw of the dice, whereas we have three throws of the dice and that’s a nice position to be in. We have to make sure on and off the pitch the atmosphere is generated in the stadium, hopefully we’ll have a special night.”
Though a point would be enough to seal second place in Group C with two fixtures to go, Northern Ireland would still like more to enhance their prospects of progressing to the play-offs.
One of the nine group runners-up in the European section will miss out and O’Neill’s team have 10 points, with 11 enough to bag a play-off berth.