Day two of the arena Pro Swim Series at Mesa, AZ, is in the books. While there were a good amount of impressive times posted on Friday night, ​Katie Ledecky​ (surprise, surprise) and ​Chase Kalisz ​were certainly the stars. Then again, that is what Olympic medalists do -- they swim fast regardless of the time of year or season. Both Ledecky and Kalisz were able to put their names in the top five of the world leaderboard.​

So, what happened? Let's take a look.

Women's 400m IM

1.) Mary-Sophie Harvey -- 4:38.05
2.) Katie Ledecky -- 4:38.16
3.) Madisyn Cox -- 4:40.37

After her runner-up finish in the 400m IM (4:36.60) at the Canadian Swimming Trials last week, ​Mary-Sophie Harvey​ made her way to Mesa to take the win in 4:38.05. Harvey had almost a full two-second lead over ​Katie Ledecky​ at the 300m mark, but here... comes... Ledecky. She made a serious push on the freestyle leg to pull up to Harvey but ultimately ran out of room and touched second in 4:38.16 -- an impressive swim for an off-event. ​Madisyn Cox​ touched third with a solid 4:40.37.

Men's 400m IM

1.) Chase Kalisz -- 4:11.01
2.) Josh Prenot -- 4:17.72
3.) Sean Grieshop -- 4:22.07

​In a day and age when facts are optional, this one is indisputable: ​Chase Kalisz​ is really, really good at the 400 IM. Since 2013, Kalisz has owned this event hands down for the American men, and Friday night was no different. Kalisz blew the field out of the water with an impressive 4:11.01 -- the fourth-fastest time in the world this year. Not too shabby for an early-season meet. The Olympic silver medalist dominated from start to finish. With a full-second lead over the runner-up ​Josh Prenot ​after the butterfly leg, Kalisz never looked back. Prenot, who touched second in 4:17.72, actually out-split Kalisz on the breaststroke leg, but it was too little too late. ​Sean Grieshop​ rounded out the podium in third with a 4:22.07.

Women's 200m Freestyle

1.) Katie Ledecky -- 1:56.31
2.) Leah Smith -- 1:58.47
3.) Simone Manuel -- 1:58.98

What does ​Katie Ledecky ​do with a short turnaround between events -- after the 400 IM no less? She wins the 200m freestyle with a 1:56.31 -- the fourth-fastest time in the world this year. Plain and simple: Ledecky is a racer. It does not matter when or where. The surprising part about this race was that Ledecky flipped second at the 100m mark in 57.54 -- only 0.04 of a second behind ​Simone Manuel​, who is known for her speed. Ledecky then turned on the jets to bury the field and take the win. ​Leah Smith​ came from fourth at the 100 to finish second in 1:58.47. Manuel faded a bit to finish third in 1:58.98.

Men's 200m Freestyle

1.) Dylan Carter -- 1:48.45
2.) Joao De Lucca -- 1:49.51
3.) Cristian Quintero -- 1:49.59

The men's 200m freestyle was a strategic game of cat and mouse between the top three finishers. ​Dylan Carter​ held the lead at the 100m mark in 52.70 over ​Joao De Lucca​ (53.08) and ​Cristian Quintero​ (53.19). But De Lucca dropped the hammer on the third 50, splitting a 27.78 to take the lead going into the final 50 meters. Carter said, "not so fast," and switched it into another gear to drop a 27.48 and take the win with a 1:48.45. De Lucca split a 28.65 over the final 50 meters and settled for second in 1:49.51. Quintero made a move on De Lucca at the end but ran out of room and touched for third in 1:49.59.

Women's 200m Backstroke

1.) Eva Merrell - 2:11.63
2.) Erin Voss -- 2:12.01
3.) Claire Adams -- 2:13.93

​Eva Merrell​ of Aquazot Swim Club led this one from start to finish. The youngster out of California built a second-and-a-half lead at the 100m mark (1:03.85) and paced pretty evenly on the back half to take the win in 2:11.63. ​Erin Voss​ made a huge push over the final 50 meters, out-splitting Merrell 32.74 to 32.80, but ran out of room and touched for second in 2:12.03. Texas Longhorn ​Claire Adams​ rounded out the podium in third with a 2:13.93.​

Men's 200m Backstroke

1.) Jacob Pebley -- 1:56.88
2.) Arkady Vyatchanin -- 1:58.61
3.) Sean Lehane -- 2:00.66

​Jacob Pebley​ continued his hot streak in the 200m backstroke throughout the arena Pro Swim Series. In Austin, Texas, he won with a 1:55.95. In Indianapolis, he touched second with a 1:55.56 (behind China's ​Jiayu Xu​ in 1:55.04 -- who just scared the 100m back WR with a 51.86). Friday night in Mesa, he led wire-to-wire and took the win with a 1:56.88. Pebley still holds the fourth-fastest time in the world this year with his 1:55.56 in Indy. The 2016 Olympian swam a very controlled race and was the only one in the field to split sub-30 on every 50. ​Arkady Vyatchanin​, the ageless wonder at 33, got his hand on the wall for second in 1:58.61, and ​Sean Lehane, ​a former Tennessee Vol, rounded out the podium in third with a 2:00.66.

Women's 50m Freestyle

1.) Simone Manuel -- 24.66
2.) Madison Kennedy -- 24.99
3.) Lia Neal -- 25.14

​Surprise, surprise -- ​Simone Manuel ​takes the cake in the women's 50m freestyle with a solid 24.66. Manuel is the 2016 Olympic silver medalist (24.07) but has a lot of work ahead of her to compete with Swedish sensation ​Sarah Sjöström​, who rattled off a blistering-fast 23.83 in Stockholm this past week. ​Madison Kennedy​ snuck under the 25 barrier to touch for second in 24.99, and ​Lia Neal​, Manuel's good friend and training partner, rounded out the podium in third with a 25.14.

Men's 50m Freestyle

1.) Ari-Pekka Liukkonen -- 21.94
2.) Nathan Adrian -- 22.25
3.) Daniel Hunter -- 22.53

This was certainly the most surprising result of the night. All credit to ​Ari-Pekka​​ Liukkonen​,​ who touched first in 21.94, but the 6-foot-10 giant from Finland has not been relevant on the international stage for a few years now. From 2011-13 he was consistently swimming 22 mids in the 50m freestyle. He had a breakout swim in 2014 at the European Championships where he earned a bronze medal with a 21.93. But in 2015, he was back to a 22.54 at the World Championships. In Rio, he swam a 22.25 and missed making the semifinals by 0.015 of a second. Regardless, any sub-22-second performance is to be applauded. ​Nathan Adrian​ touched for second in 22.25, and ​Daniel Hunter​ grabbed the bronze with a 22.53.