After the first day of the 28th Monte Carlo International Hannah Miley (GBR) with her winning time in the 400 individual medley in 4:35.06 posted the top swim for the day, and improved her seasonal best by two seconds.

Breaststroker Rebecca Soni (USA) continued her unbeaten streak for 2010 with a win inthe 100 in 1:06.53, off her seasonal best of 1:05.90.

Dana Vollmer (USA) won the 100 fly in 58.91 just off her winning time last weekend half-way around the world in Vancouver with 58.59.

Sinead Russell (CAN) won the 200 backstroke in 2:10.93 improving on last year's best of 2:13.83.

One of the highlights of this competition are the sprint 50s, three rounds were held on the first day, and two more on the second, the final being contested with the top two in each stroke.

Top women sprinters after the first day were Yulia Efimova (RUS) with 30 64 in the 50 breast, Therese Alshammr (SWE) in the 50 fly with 26.01, Jing Zhao (CHN) with 28.13 for 50 back, and Ranomi Kromowidjojo (NED) 24.96 in the 50 free.

Top men's performance was Eric Shanteau (USA) in the 200 breaststroke in 2:11.51 in a very strong field including 2009 World winner Daniel Gyurta (HUN) in 2:12.23, and 2008 Olympic winner Kosuke Kitajima in 2:12.27.

Brent Hayden (CAN) won the 100 free in 49.18, Camille Lacourt (FRA) won the 100 back in 53.97 and Markus Rogan (AUT) won the 200 individual medley in 1:59.80.

Paul Biedermann (GER) posted his seasonal best of 3:48.77 in the 400 free.

Leaders in the stroke 50s are Ashley Callus (AUS) 22.39 for free, Daniel Arnmanrt (AUS) 25.79 for 50 back, Stanislav Lakhtyukhov (RUS) 28,13 for 50 breast, Geoff Huegill (AUS) 23.89 for 50 fly.