The two nations are level at the bottom of Group G on one point apiece, but Ghana is in a slightly better position given its superior goal differential.
The Ghanaians suffered a 2-1 defeat to the United States to open the tournament, a disappointing result given that they controlled large portions of the match but came away empty-handed.
But the response from Akwasi Appiah's men was fantastic. They faced Germany, one of the pre-tournament favorites, and had the European nation on the ropes in the second half. Goals from Jordan Ayew and Asamoah Gyan helped overturn Mario Gotze's opener, but the Germans claimed a share of the spoils behind a patented Miroslav Klose poached strike.
"It was a good game," Appiah said. "Germany are one of the best teams in the world and we gave it our all. We had some chances but unfortunately if you don't take them against big teams then you don't end up winning. We also wasted a few opportunities to equalize against USA, but that's in the past now.
"I always had faith because we fight to the end. I believe attack is the best form of defense and that's what we tried to put into practice. I always believed in my players and that we could win. It won't be easy to reach the round of 16 because we've only got one point. There are still a few games left to play in our group and although it'll be tough, it is possible. You can only stop Cristiano Ronaldo, the best player in the world, by working as a team. We can't let him show what he can do."
Ghana's efforts to contain Ronaldo should be aided by the fact that he is clearly not at full fitness. The Real Madrid star has been battling a knee injury for the duration of the tournament and has struggled to get going, but he proved with a splendid cross on a late equalizer against the United States that he only needs one moment to an impact.
Of course, Portugal still has a mountain to climb after digging itself a massive hole with a 4-0 loss to Germany in its opening match.
"Things still look pretty bleak for us," said Silvestre Varela, who scored from Ronaldo's last-minute cross against the United States to keep Portugal alive in the tournament. "We wanted the win and we're a bit down about how the game went. We have to keep on believing though.
"Playing for Portugal gives us strength and we'll fight till the last minute. That's what the team did. We battled and battled, even if it wasn't enough to get the win. We now have to go and win our last game and hope that things happen elsewhere."
At the end of the day, though, a Portugal defeat of Ghana may not be enough for Paulo Bento's men. Not only do they need three points from Thursday's match, but the scores of both games matter given their sizable deficit in goal difference.
"It's clearly not a good result for us," Bento said after the draw to the Americans. "The 2-2 doesn't put us out of the World Cup mathematically, but it does leave us in a very difficult situation. Not just because of what we'll need to do against Ghana, but also because we'll need a favorable result from the Germany-United States game.
"We were unlucky late in the first half, but it was a great effort to level the match (in second-half stoppage time). Now all we can do is to give everything in our very last game and try and make the most of the very little chance that we have left."