ROME: Six world records tumbled on the first night of World Championship swimming on Sunday, but with the record books turned upside down Michael Phelps ended up in a familiar spot — the winner’s podium.

The half-dozen records yielded in the evening’s eight events at the Foro Italico included two in one event, and while Phelps wasn’t part of the spree he did have a role in America’s upset victory in the men’s 4x100m free.

Italy’s Federica Pellegrini thrilled home fans by lowering her own world mark to win the women’s 400m Freestyle, and German Paul Biedermann also notched a world record in winning the men’s 400m free.

The Netherland’s Olympic gold medal-winning women’s 4x100m freestyle relay team lowered their world record to add a world title to their list — overcoming an individual 100m freestyle world record for Germany’s Britta Steffen in the lead-off leg of that race.

Swedish teen Sarah Sjostrom and American Ariana Kukors nabbed their world records in semi-finals — Sjostrom in the women’s 100m butterfly and Kukors in the women’s 200m individual medley.

The men’s 4x100m free relay didn’t produce a world record, just scintillating racing in which an American team led by Phelps and anchored by Nathan Adrian triumphed, Russia snatched silver and France’s vaunted freestyle sprinters took bronze.

Three world records fell in the first three events, starting with Sjostrom’s 56.44sec in the women’s 100m fly semis. That broke one of the oldest records on the women’s books, the 56.61sec set by Inge de Bruijn of the Netherlands at the Sydney Olympics in 2000.

Next up was Biedermann, whose 400m freestyle victory in 3:40.07 broke an iconic mark, the 3:40.08 set by Australian legend Ian Thorpe in 2002. Biedermann beta Tunisian Oussama Mellouli to lift the crown, Mellouli finishing second and China’s Olympic silver medallist Zhang Lin third.

World record number three went to unheralded Kukors. She clocked 2:07.03, to better a mark held by Australian Stephanie Rice, who settled for the second-fastest semi-final time. For more than 11,000 Italian fans, however, the high point was Pellegrini’s 400m free triumph, with a time of 3:59.15 that made her the first woman to break the four-minute barrier. Briton Joanne Jackson, who held the record earlier this year, settled for silver ahead of compatriot Rebecca Adlington.

In the women’s relay, the Dutch quartet of Inge Dekker, Ranomi Kromowidjojo, Frederike Heemskerk and Marleen Veldhuis rallied from fifth after the first leg to win in 3:31.72. Germany settled for silver, despite the record-breaking exploit of Steffen, who led off in an individual record of 50.22sec, and Australia captured bronze. Germany’s time of 3:31.83 and Australia’s 3:33.01 were both under the previous relay world record.