Rory McIlroy and Matt Fitzpatrick lost their match to Patrick Cantlay and Wyndham Clark.
Everything was decided on the last hole.
When McIlroy was about to putt shortly after Cantlay made his putt, he was disturbed by the opponent's caddy.
"I was there on the 18th green. I saw what happened when Cantlay put the putt. Joe Lacava (the caddy) waved his cap. Rory (McIlroy) politely asked him to move because he was standing in the way. But he stood still and kept waving his cap," Luke Donald said.
McIlroy missed, lost the match, and then a big brawl broke out in the parking lot where McIlroy confronted his opponents.
"The Ryder Cup is always passionate. We go out with twelve strong players tomorrow and I won't make any decisions based on what happened," Donald said.
"This will be lighter fluid for tomorrow," Rory McIlroy said immediately after the loss on the 18th green.
Europe leads 10.5–5.5 going into the final singles rounds. McIlroy and Cantlay do not face each other.
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