Swimming kicked off day one of the Olympic Games in fine fashion, complete with several jaw-dropping moments, come from behind wins, disappointments and the first of two matchups between Ryan Lochte and Michael Phelps.
The day began with numerous preliminary heats.
Once the tables were set, it was on to the finals in the men's 400-meter freestyle, women's 4x100-meter freestyle relay, and both men's and women's 400-meter individual medley.
July 28 saw 28 heats, four semifinals and four finals competitions.
Here are the highlights from all 36 races.
Michael Phelps qualified for the men's 400-meter individual medley after finishing first in the fourth heat with a time of four minutes, 13.33 seconds.
It's worth noting that Phelps clearly slowed himself at the end—something many swimmers do in qualifiers to conserve energy.
The move almost cost him though.
Phelps' time qualified him for the eighth and final spot of the finals.
The second place finisher in the fourth heat—Hungary's Laszlo Cseh—finished with a time of 4:13.40.
Phelps made it in by .07.
Japan's Kosuke Hagino
In order, the eight qualifiers for the men's 400-meter individual medley finals were:
Kosuke Hagino (JPN): 4:10.01
Chad le Clos (RSA): 4:12.24
Ryan Lochte (USA): 4:12.35
Thiago Pereira (BRA): 4:12.39
Thomas Fraser-Holmes (AUS): 4:12.66
Luca Marin (ITA): 4:13.02
Yuya Horihata (JPN): 4:13.09
Michael Phelps (USA): 4:13.40
As you can see, outside of Hagino, the finalists were separated by no more than a second.
Another interesting note, five of the finalists (le Clos, Lochte, Fraser-Holmes, Marin and Horihata) came from the fifth heat.
The top 12 competitors in the men's 100-meter breaststroke competition—including two Americans (Brendan Hansen and Eric Shanteau)—finished with times under one minute.
Even more impressive, the dozen were separated by less than three-tenths of a second.
Take a look:
Christian Sprenger (AUS): 59.62
Kosuke Kitajima (JPN): 59.63
Giedrius Titenis (LTU): 59.68
Daniel Gyurta (HUN): 59.76
Glenn Snyders (NZL): 59.78
Cameron van der Burgh (RSA): 59.79
Scott Dickens (CAN): 59.85
Ryo Tateishi (JPN): 59.86
Michael Jamieson (GBR): 59.89
Brendan Hansen (USA): 59.93
Eric Shanteau (USA): 59.96
Fabio Scozzoli (ITA): 59.99
First place and 12th place are differentiated by .37 seconds.
Cameron van der Burgh later set an Olympic record in the semifinals with a time of 58.83.
The finals are July 29.
China's Yang Sun provided his country with a gold medal, finishing first in the men's 400-meter freestyle.
His time of three minutes, 40.14 seconds was not only an Olympic record, but placed him nearly two full seconds ahead of second place finisher Taehwan Park (KOR).
Peter Vanderkaay of the United States finished third.
American swimmer Dana Vollmer swam to a personal best, American best and Olympic-record time of 56.25 seconds in the women's 100-meter butterfly.
The next closest was China's Ying Lu with 57.17—almost one full second slower.
Vollmer is the clear front runner in the July 29 finals.
Elizabeth Beisel hugs gold medalist Shiwen Ye
Elizabeth Beisel—the 19-year-old American swimmer—qualified for the women's 400-meter individual medley with the fastest time of all five heats.
Her finish time of four minutes, 31.68 seconds is 2.23 seconds short of the world record held by Australia's Stephanie Rice.
Rice finished seventh.
After leading all morning, however, Beisel was upset in the finals by China's Shiwen Ye.
Ye's time of 4:28.43 is the new Olympic and world record. It is also nearly three seconds faster than Beisel's finish time.
The men's 400-meter individual medley finals provided the first upset of sorts of the 2012 Olympic Games.
In a shock to many, favorite Michael Phelps finished fourth.
Phelps' rival and fellow American swimmer Ryan Lochte will bring home the gold medal instead.
Not only did Lochte win, he smashed the competition.
His four minutes, 5.18 seconds was a full three seconds faster than the next best time.
So far it appears Lochte's offseason preparations are paying off. Phelps meanwhile may already be looking forward to retirement.
It will be interesting to see how Phelps responds in their next and final head-to-head competition. You have to imagine he won't take a fourth-place finish lightly.
Interestingly enough, the other three finals competitions from July 28 all saw blowouts of two- or three-second leads.
That didn't happen in the women's 4x100-meter relay.
Australia won the gold medal, setting a new Olympic record with a time of three minutes, 33.15 seconds. However, second place Netherlands finished at 3:33.79—just .64 seconds behind.
The United States earned the bronze, finishing in 3:34.24—.36 behind Netherlands.