Robert MacIntyre, competing directly against Scottie Scheffler at the BMW Championship, sparked a "Ryder Cup effect" among the fans, who passionately supported the American while attempting to unsettle the Scot.Tensions escalated on the 14th hole, where MacIntyre turned to the crowd and told them to "shut it."On the 14th hole, Scheffler drained an 18-foot birdie putt, narrowing the gap to just three shots off the lead, prompting thunderous cheers from the crowd. MacIntyre followed with a composed 7-foot par putt and, after apparently receiving far fewer friendly remarks, raised a finger to his lips in the universally recognized "shush" gesture.When asked after the round if the crowd's boos and jeers fired him up, MacIntyre responded, "100%.""It can go two ways," he said after his third-round performance. "But look, I grew up all my days amateur golf being the one on the outside looking in, faced not fitting, really fighting for it. What we say in the team, it's not the size of the dog in the fight, it's the size of the fight in the dog, and I grew up fighting to be in this position."Naturally, this crowd reaction was not at all unexpected for MacIntyre, considering he is not only playing against the world No. 1, but also against the top American star with just six weeks to go until the Ryder Cup."I totally expected it," he said. "I totally expected to be in this situation today when I'm in this position. It's going to be the exact same tomorrow. Yeah, I'll give as good back as I get."MacIntyre also revealed that what happened on the 14th hole was far from the only rough moment with the fans, but that it doesn't bother him as long as they maintain the common golf tournament rules."It started on the first tee," he said. "It probably started when I walked down to the range. It ain't bothering me. It's there. As long as they don't do it within -- if they do it outside the shot, it's fair game, but don't do it within the shot that's going to affect myself or Scottie."With just 18 holes remaining, MacIntyre holds a four-stroke lead over Scheffler at the BMW Championship. The two will again play together in the final group for the final round, so large crowds are once again expected.The day will be a tremendous prelude to the Ryder Cup, which will be played in September at Bethpage Black, just over 200 miles northeast of Caves Valley Golf Club. Scheffler is already a lock to be on the American team, while MacIntyre could secure his spot if he wins the BMW Championship.More Golf: Phil Mickelson wades barefoot, chips out of trouble at Indianapolis