CHASKA, Minn. -- Even with the first opening-session sweep in four decades, the Americans were reminded anew Friday that no lead is safe in the Ryder Cup.Not after one session. Not after one day.And based on the last Ryder Cup on American soil, not until its over.Europe battled back from a 4-0 deficit behind its best tandem, Henrik Stenson and Justin Rose, and capped off a long and rowdy day at Hazeltine when its best player, Rory McIlroy, holed a 20-foot eagle putt and then mocked the crowd by taking a bow.The American celebration turned into a consolation.They had a 5-3 lead, the margin after the first day at Medinah four years ago that ended in another European victory. They lost a chance to really put Europe in a hole.Its frustrating not to come out a little bit more ahead, U.S. captain Davis Love III said.Love could not have scripted a better start -- a symbolic one, too. To honor Arnold Palmer, who died Sunday night, Ryder Cup officials placed on the first tee Palmers golf bag from when he was captain of the 1975 Ryder Cup team.Jordan Spieth and Patrick Reed then set the tone with a 3-and-2 foursomes victory over Stenson and Rose, and the Americans delivered the first sweep of the opening session since that 1975 team at Laurel Valley.Phil Mickelson, feeling more pressure than usual because of his influence on changes and on this team, also produced big shots. His wedge into 5 feet that Rickie Fowler converted was key in the Americans winning three straight holes for a 1-up victory over McIlroy and Andy Sullivan.With everything going on -- me not having a point and Phil being a big part of getting the players a lot more involved to Arnie passing and him being a huge part of the week, this is big for us, Fowler said.It just didnt last.The guys were disappointed with the way they played this morning and the way they performed, European captain Darren Clarke said. But they showed tremendous bravery and heart and desire to go out and play the way they have done this afternoon.Beaten for the first time, Rose and Stenson went right back out against Spieth and Reed and handed the American duo its first Ryder Cup loss. The Europeans made nine birdies in 13 holes for a 5-and-4 victory in an afternoon session in which the board was filled with European blue.Sergio Garcia, who along with Martin Kaymer made only one birdie in a foursomes loss, teamed with fellow Spaniard Rafa Cabrera-Bello to dismantle J.B. Holmes and Ryan Moore.McIlroy and Thomas Pieters never trailed against Dustin Johnson and Matt Kuchar, handing them their first loss in four Ryder Cup matches.The lone American point in the afternoon came from Brandt Snedeker and Brooks Koepka, who had no trouble against Kaymer and Danny Willett.Willett had a little trouble with the crowd, especially when they lampooned him around Hazeltine with references to hot dogs and his brother, Pete, who had written a column in a British publication disparaging American galleries.It was anticipated, Willett said. Coming to America is a tough one, just like when the Americans come to Europe. They gave me a little bit more. I think it was exactly what we thought it was going to be.It wasnt just directed at Willett, however. The crowd was loud and boisterous from the opening tee shot in misty conditions. There were a few rude comments, not unusual in America for a Ryder Cup.McIlroy had a 20-foot birdie putt to halve the morning foursomes match against Mickelson and Fowler when a fan from across 100 yards away shouted, Get an American to putt it for you.That was a reference to McIlroy and Rose losing a playful $100 bet to an American fan who made a putt in Thursdays practice session.?Most striking was how quickly the crowd cheered bad shots for Europe. Typically, there is the slightest delay.Not on Friday.Sullivan, one of six rookies for Europe, hit his tee shot into the water on the 17th that put Europe 1 down and effectively ended the match. The crowd cheered before there was a ripple.Thats what inspired McIlroy in the final match of the day. He and Pieters were 2 up on the 16th hole, with Kuchar already in for a birdie, when the four-time major champion drained his 20-foot putt. Turning to the crowd, he bowed twice and screamed out, Cmon!I wanted to put an exclamation on that session for us, McIlroy said. I thought about that celebration before I hit the putt.More than a celebration, it was a message from McIlroy to what he felt was a hostile crowd.Im not fazed by anything said by the crowd, McIlroy said. And Im not fazed by anything the U.S. throws at us.The late European comeback bought captain Clarke enough breathing room to get the last two of his six rookies on the course at the start of Round 2.His opening and anchor duos for Saturday mornings foursomes will be familiar: McIlroy-Pieters and Garcia-Cabrera Bello, respectively, already played together in Round 1. In between those pairs, Stenson and Rose will split an