It's not every day that a Cardinal athlete sets a world record, so this is worthy of our attention.

From U of L:

University of Louisville senior Kelsi Worrell set both a World and American record in her first night of competition at Duel in the Pool in Indianapolis

The American 400-Medley Relay team of Courtney Bartholomew (56.08), Katie Meili (1:02.88), Kelsi Worrell (55.01), Simone Manuel (51.23) combined for a World Record time of 3:45.20. Manuel had to hold off a charging Ranomi Kromowidjojo to clinch the Americans' team win with her anchor leg. Europe finished in 3:45.46.

In the 100-fly, Worrell may have touched the wall second but she set an American record in the process Danish sprinter Jeanette Ottesen, won with an blazing 55.10, shaving .2 off her previous best. Worrell's time of 55.42 set a new American Record, besting the former mark of 55.59 set by Dana Vollmer. Worrell's splits were 25.95/29.47, outsplitting Ottesen (25.44/29.66) down the stretch.

This year marks the seventh Mutual of Omaha Duel in the Pool, held every other year since 2003. The U.S. is undefeated and holds a 6-0 all-time record in the competition.The 2013 event came down to a tie breaking mixed 4 x 50m medley relay, won by the United States to claim the overall meet victory and preserve its undefeated 6-0 streak since Duel in the Pool started in 2003.

The Ryder Cup-style event is a 25m short course dual meet held over two days with no prelims or semis - only finals. There are 15 events for men and 15 for women, where athletes can score five points for first place, three points for second and one point for third place. Seven points are awarded to winning relays. The first team to reach 131.5 points wins.

NBC will air coverage of the meet Dec. 19 from 4-6 p.m. ET.

The Mutual of Omaha Duel in the Pool will be contested in downtown Indianapolis over two sessions: Friday, Dec. 11 at 7 p.m. ET and Saturday, Dec. 12 at 2 p.m. ET. Adult all-session tickets cost $65, $50 and $35 depending on location; Children's (ages 12 and under) all-session tickets are $55, $40 and $25. Single-session tickets are also available beginning at $20 for adults and $15 for children. All tickets are for reserved seating. Tickets can be purchased via usaswimming.org.