The first day of the Arena Pro Swim Series in Mesa, Arizona saw Americans take first place in the majority of the contests.

In the women’s 200m freestyle Katie Ledecky continued her winning ways making it four out of four in the series so far. Allison Schmitt had her top finish of the year in second place as the top two were well out in front of the rest of the field. Over on the men’s side similar dominance was shown by Connor Dwyer who made it three for three and finished a second a half ahead of everyone else. Ryan Lochte finished third as Venezuelan Cristian Quintero slipped between the two Americans.

Over in the women’s 100m breaststroke Katie Meili won her second in two tries this year with Jamaican Alia Atkinson and Molly Hannis both within a half second of her. The men’s 100m breaststroke had one of the best finishes of the day as Andrew Wilson, Youssef El Kamash of Egypt, Miguel De Lara Ojeda of Mexico, and Azad Al-Barazi of Syria, all finished within 0.07 seconds. El Kamash got the win with De Lara Ojeda in second and Wilson the top American in third.

Dana Vollmer, having finished twice so far this year, finally won the women’s 100m butterfly while Kelsi Worrell was runner-up a third of a second back and Cassidy Bayer almost two seconds back in third. On the men’s side Seth Stubblefield, who had yet to register a top ten finish in two attempts this year, won the event with Jack Conger, ninth in his only appearance so far, in second. Giles Smith was third and now has finished at every top-five spot except for second in the first four races of the year.

Finally in the women’s 400m medley Katinka Hosszu of Hungary won for the second time this year while Cammile Adams added a second place finish to her two previous top-five finishes and Ella Eastin in her first appearance was third. On the men’s side Sean Grieshop, sixth in his only previous appearance, won by over three seconds with Tunisian Ous Mellouli in second and Gunnar Bentz with a third place finish in his first race.

Friday features races in the 200m butterfly, 50m freestyle, 100m backstroke, 200m breaststroke, and 400m freestyle. Preliminaries in the morning, finals in the evening.

Cammile Adams has won both of her attempts at the 200m butterfly and also in the field is Cassidy Bayer who was third in her only attempt so far and Maya DiRado who won the event in Orlando. On the men’s side Michael Phelps will race, second in his only entry so far this season, as will Andrew Seliskar, third in Austin, and Chase Kalisz who won in both Minneapolis and Orlando.

Top contenders in the women’s 50m freestyle include Madison Kennedy, first in Orlando and second in Austin, and Simone Manuel, who was second in both of her races so far this season. On the men’s side Nathan Adrian has won each of the first three events of the series and will look to make it four-for-four while Jimmy Feigen, third in his only appearance, is also in the field.

In the 100m backstroke Missy Franklin, who has won two of the three events so far, will go head-to-head against the only one to beat her so far this year, Katinka Hosszu of Hungary. On the men’s side David Plummer, who won in Minneapolis and came in third in Austin, is the only of the first three winners to compete this weekend perhaps making him a favorite.

Three Americans with good finishes so far this year will all compete in the 200m breaststroke Laura Sogar was the winner in Austin while Molly Hannis finished right behind her. Haley Spencer finished second in Minneapolis. This will be only the second competition for all three. On the men’s side Nic Fink has finished second in all three events so far but just might get his first win as the winners from the first the first three races are not competing.

Finally in the 400m freestyle there are a lot of good swimmers in the field but it’s clearly headlined by Katie Ledecky, who won the two events she raced in so far this year. Also competing is Lotte Friis who won the other and was fourth in her other attempt. Connor Dwyer is two-for-two winning the men’s 400m freestyle but Michael McBroom, who was second in his only competition so far, will provide competition.