Europe and the United States will battle it out in the 44th edition of the Ryder Cup in Rome this week, with the Americans bidding for their first away victory in 30 years.
Here, AFP Sport takes a look at five of the most controversial moments from previous Ryder Cups:
1989: Seve and Azinger
Paul Azinger and Seve Ballesteros went head-to-head in a tense lead-out singles match at The Belfry. The European star requested to have a damaged ball replaced but Azinger successfully objected. Ballesteros hit back by later asking whether Azinger had properly dropped his ball after hitting it into a water hazard on the 18th hole. Azinger held on to win the match 1-up, but Europe retained the trophy following a 14-14 tie.
1991: 'War on the Shore'
The tone for the 1991 matches was set when some of the Americans arrived on the first day wearing camouflage caps in a nod to the first Gulf War which finished earlier that year. The USA team were repeatedly accused of gamesmanship by Europe as the hosts won 14.5-13.5 at Kiawah Island.
Azinger and Ballesteros again clashed over accusations the American and his partner Chip Beck had changed balls. Later in the week, Raymond Floyd hit out at Ballesteros, claiming he was deliberately coughing during his swing. The US were also widely criticised for saying Steve Pate could not feature in the Sunday singles due to injury, despite having played the previous day, earning an automatic half point from his scheduled match against David Gilford.
1999: 'Battle of Brookline'
Another heated encounter was preceded by American Payne Stewart saying "on paper, they (Europe) should be caddying for us". Colin Montgomerie said his father had to leave the course due to abuse from the home fans, while Europe's Mark James alleged a spectator spat at his wife. The USA did eventually edge to another one-point victory after trailing 10-6 heading into the singles, but there was huge controversy in the deciding match between Justin Leonard and Jose Maria Olazabal.
Leonard holed a 40-foot putt on the 17th hole, sparking wild celebrations as American players, family members and cameramen ran onto the green. Olazabal still had a putt of his own to keep the Ryder Cup alive but missed, with Europe left fuming over the USA's apparent lack of etiquette.
2014: Mickelson criticises Watson
In the post-tournament press conference following the USA's defeat at Gleneagles, Phil Mickelson said the Americans had "strayed from a winning formula" in comments widely considered as a thinly-veiled attack on captain Tom Watson who was sitting a few seats down on the same table. Watson refused to respond in kind at the time, but the following year he accused Mickelson of "sour grapes". Mickelson had been left out of both sessions on the Saturday.
2018: Reed v Spieth
Patrick Reed and Jordan Spieth formed a fantastic partnership for the United States at the 2014 and 2016 Ryder Cups, winning five points from seven matches and only losing once. But they were surprisingly not paired together for the 2018 edition in France by captain Jim Furyk, with the US going on to suffer a heavy defeat. Reed's wife claimed on Twitter that he had never asked not to play with Spieth. Following the tournament, Reed told the New York Times that the reason the duo were split up was because of "Jordan not wanting to play with me”.
Despite a stellar Ryder Cup record, Reed had been left out of both afternoon sessions on the Friday and Saturday following morning losses alongside Tiger Woods. He was one of only four Americans to win in the singles. "I don't think it's smart to sit me twice," he said. Reed has not played in the competition since.
AFP