All's fair in love, war and relegation battles - or Palmeiras seem to think so.
The Sao Paulo giants, the team of the city's Italian community, are in trouble. Back in July they won the Brazilian Cup, guaranteeing a place in next year's Copa Libertadores, South America's Champions League.
However, results have since suffered in the domestic league and they now need to make up a seven-point gap with just four rounds of the season left.
Their hopes could perhaps rest on the outcome of a hearing to be held in the next couple of days. The focus of their appeal is a disallowed goal from Argentine centre-forward Hernan Barcos against on October 27.
Palmeiras claim referee Franscisco Nascimento allegedly used television images to disallow their equalising goal against Internacional. Photo: Getty
Barcos diverted a corner into the back of the net with his hand. The goal was disallowed, and there is no doubt that it should have been, but there is a strong suspicion that in order to make the decision the wrong means were used.
At first neither the referee nor his assistants appeared to see anything wrong with the goal. Then came the change of mind - allegedly because the referee had been informed of the handball by somebody watching a television monitor. This, of course, is a resource that is not officially available to referees.
Palmeiras, who lost the game 2-1, made a formal complaint and they are hoping the match will be declared void and a replay ordered, giving them a chance to get three points closer to safety.
Launching a complaint because an illegal goal was ruled out would seem to contravene football's unofficial rule 18 - the request that common sense be applied in the application of the 17 laws of the game. Some people, though, think Palmeiras have a case - and even if they do not, the seriousness of their situation justifies such desperate measures.
The issue here is the role of technology in the decisions taken by football referees and, perhaps an even bigger issue, the limitations of the use of technology in decisions taken by officials.
The laws are full of references to "in the opinion of the referee" and "in a manner considered by the referee...." Even off-side is a matter of interpretation.
This means that a utopia of footballing justice can never exist, however much technology is employed because there will always be different interpretations.
The easiest proof of this is to contrast the opinions of opposing players and coaches. It is one of the great truths of football that everyone always thinks the referee is favouring the other side.
Such a state of affairs is not hard to understand because football people live a life of constant insecurity. The easiest way to deny or avoid unwelcome truths is to blame the referee.
Diego Alonso stands out in this respect - one of the reasons for believing the 37-year-old Uruguayan is one of the most promising coaches in South American football.
A target man centre-forward in his playing days - good enough to have won senior international caps and to have had a fair career in Spain - Alonso knew from an early age that he wanted to be a coach.
After a short spell in charge of Bella Vista, the Montevideo club where he both started and ended his playing days, he took over Guarani of Paraguay this year, moulding an aggressive team who are closing in on a rare league title - only their second in almost 30 years.
"In training sessions," he told Uruguayan newspaper 'El Pais' last week, "we practice situations where he have had a man sent off and are in numerical disadvantage. We also stage games with biased refereeing so the players can get used to it."
He is attempting to foster a mentality where his men take full responsibility for their own performances. "The message that I pass to the players is that there is not a referee in the world who can make them lose a game. I don't deny that sometimes the referee has a bad day. But if you have real players, a referee is not going to tip the balance."
Alonso's preparation was put to the test on Sunday, when Guarani had two men sent off in their visit to Sportivo Luqueno. In the circumstances, a 1-1 draw was perhaps not a bad result. But it is Guarani's third game without a win and their lead at the top of the table has been cut to four points with seven games remaining.
As the pressure mounts, it will be fascinating to see if Alonso can maintain his line of conduct and if Guarani can keep doing the things that took them to the top of the table. As Alonso is aware, if they are overtaken they will have no one but themselves to blame.
Comments on the piece in the space provided, questions on South American football to email@example.com, and I'll pick out a couple for next week from last week's postbag;
Q: You have talked of the dearth of full backs in the Argentina national team but Pablo Zabaleta has been one of the most improved players in the Premier League. A firm fans' favourite, he is also well loved by his teammates and backroom staff alike. He speaks excellent English and has adapted well to life in Manchester. This season, along with Joe Hart, he has been City's most consistent player. He is now a regular in the Argentine team, so why don't you rate him and how is he viewed in his native country?
A: Former Argentina coach Carlos Bilardo recently commented that Argentina could find 10 possible presidents of the country, but not one full-back - which goes some way towards answering your question.
I've always seen him as a useful player. It's probably worth remembering, though, that he's not a natural full back - he was a right-sided midfielder who has been converted. As far as I'm aware, all the praise that you give him is spot on. He does seem to be an excellent character - I think the fact that he is doing well in top level football has more to do with the strength of his mentality than with any outstanding talent.
He is clearly an important figure in the Argentina squad, not least because he is prepared to play full back on either flank. It is a position, though, where Argentina need to improve. National team coach Alejandro Sabella was talking recently of the pros and cons of playing Lionel Messi, Sergio Aguero and Gonzalo Higuain. The big disadvantage, he correctly identified, is that it leaves the team vulnerable down the flanks. Left exposed, Zabaleta had an awkward time against Chile last month.
Tim Vickery is a regular guest on BBC Radio 5 live’s World Football Phone-in, which is available to download as a podcast.