Australia and Serbia have already experienced the highs and lows of this World Cup ahead of their decisive Group D encounter on Wednesday.
Australia suffered a red card in each of its opening matches, while Serbia conceded penalties in both of its games.
But on the positive side, Serbia bounced back from an opening defeat against Ghana to beat Germany, while Australia's 4-0 thrashing at the hands of the Germans was followed by a battling 1-1 draw with ten men against Ghana.
After those ups and downs, both sides are left in the position of knowing defeat in Wednesday's match at Nelspruit's Mbombela stadium could equal an early flight home.
Australia needs to win and also rely on a favorable result in the simultaneous Ghana-Germany game to reach the round of 16. If Australia and Ghana both win, Australia is through. If Germany wins, Australia must beat Serbia and hope its goal difference is boosted and Ghana's reduced by a sum of five goals. A Germany-Ghana draw would leave Australia having to win by seven goals.
For Serbia, a win guarantees progression, while a draw would also do the job provided Ghana wins.
Not much separates the two sides according to FIFA's rankings; Serbia is in 15th spot, with the Australians five places further back.
Australia's preparation has been hampered by suspensions to two key players. Forward Harry Kewell will miss out after his red card against Ghana and experienced defender Craig Moore is sidelined after picking up two yellow cards.
"They still have good players in the reserves, but these two are big players for them", Serbia captain Dejan Stankovic said. "We will try to use that to our advantage".
The brighter news for Australia is that attacking midfielder Tim Cahill is available after serving a one-match ban for his red card against the Germans.
Cahill averages a goal every second game for the Socceroos and his ability to arrive late in the box from midfield is among the national team's principal weapons.
Australia coach Pim Verbeek was pilloried for playing Cahill up front against the Germans - an experiment that probably won't be repeated, with tall striker Josh Kennedy likely to start.
"This week I have kept myself really fresh and sharp and made sure that the management can see that I'm edging to still be in selection and make sure that I try and start", Cahill said
At the back, Moore's likely replacement is Michael Beauchamp, who stands 1.91 meters (6 feet 3 inches) tall and could be a useful attribute to counter Serbia's 2.02m (6 feet, 7- ½ inch) Nikola Zigic.
Despite the collapse against Germany, Australian sports stars have a reputation for relishing competition.
"They are a very competitive, honest football team", Inter Milan midfielder Stankovic said. "They are fighters and they showed that by holding Ghana with 10 men. We expect them to come out fighting".
"They have a good collectiveness. We respect their quality, but we will do our best to beat them".
Serbia can count on players from some of Europe's top clubs. Nemanja Vidic is a regular in the center of Manchester United's defense, while Branislav Ivanovic impressed with Chelsea in the season past.
Inter Milan midfielder Stankovic is fresh from victory in the UEFA Champions' League and also carries the distinction of playing in his third World Cup - each time for a different nation. He represented the former state Yugoslavia in the 1998 World Cup and for the combined Serbia and Montenegro four years ago. The latter union was dissolved the same year when Montenegro declared independence.
Serbia will have defender Aleksandar Lukovic available after his one-game suspension, but six other players are carrying yellow cards and in danger of picking up a suspension for the round of 16.
The situation has prompted coach Radomir Antic to look at alternatives ahead of this decisive match.
"My philosophy is not based on individual play", Antic said. "In order to succeed you need teamwork. Every individual brings something to the table which helps to mold us as a unity."