June 22 (Reuters) - Spaniard Jon Rahm"s thrilling victory at last weekend"s U.S. Open vaulted him past American Justin Thomas and into the top spot in the final Olympic Golf Rankings, which were released on Tuesday. Americans rounded out the top five with Thomas, Collin Morikawa, Xander Schauffele and Bryson DeChambeau expected to represent Team USA this summer in Tokyo. World number two Dustin Johnson had previously said he would not compete in the men"s tournament, which will be held from July 29 to Aug. 1 at the Kasumigaseki Country Club, clearing the way for DeChambeau to take the fourth U.S. spot. Patrick Cantlay will serve as the first alternative for the American contingent, which will be the largest as no other country has more than two qualifiers in the 60-player field. Notable players who also finished in the top 10 include Ireland"s Rory McIlroy, Norway"s Viktor Hovland, Japan"s Hideki Matsuyama, Great Britain"s Paul Casey and Mexico"s Abraham Ancer. Rahm"s countryman Sergio Garcia has said he made the difficult decision to skip the Olympics to focus instead on the Ryder Cup, which pits a team from the United States against a team from Europe. Justin Rose, who took home the gold in Rio in 2016, is Great Britain"s first alternate. The women"s rankings will be finalized after the Women"s PGA Championship, which tees off on Thursday. The 60-player women"s competition will be held at Kasumigaseki Country Club on Aug. 4-7. Reporting by Rory Carroll in Los Angeles; Editing by Ana Nicolaci da Costa Our Standards: The Thomson Reuters Trust Principles.