A record run

Lakeville 17-year-old Regan Smith set two world records Sunday at the swimming world championships, giving her three for the weekend. Her 57.57-second time in the 100-meter backstroke, the first leg of the 4x100 medley relay, set one record while her team's time of 3:50.40 set another world mark.

Smith's first-leg time beat the previous mark of 58 seconds set by teammate Kathleen Baker at the 2018 U.S. National Championships. And the relay team (Lilly King, Kelsi Dahlia, Simone Manuel and Smith replacing Baker in the backstroke) broke its own 2017 record of 3:51.55. Here's a split comparison of the 2017 team and this year's gold medalists:

2017 Stroke 2019

58.58 (Baker)Backstroke(Smith)57.57

1:04.48 (King)Breaststroke(King)1:04.81

56.30 (Dahlia)Butterfly(Dahlia)56.16

52.23 (Manuel)Freestyle(Manuel)51.86