Day 3 of track and field competition has come and gone. Many events are still hashing themselves out, but exciting final heats have already decided several important medal winners.

The men's 100-meter dash, perhaps the most anticipated track event, reached its decisive conclusion in the day's final event, while the men's 1500 final field was set.

The women's 400 champion was determined on Sunday as was the women's triple-jump champion and marathon winner.

All of these events, and others, made Sunday an exciting day in this section of the Olympic spectrum.

Let's take review Sunday's action.

*For full track and field schedule, click here.

Usain Bolt successfully defended his 100-meter dash title in Sunday's final. Bolt started slow, but he used the final 50 meters to run away with the gold medal. His 9.63-second run earned him an Olympic record, besting the mark he set in 2008.

Fellow Jamaican Yohan Blake finished second with a 9.75, and three Americans finished in third, fourth and fifth. Justin Gatlin led the group with a 9.79 and a bronze medal.

This is certainly disappointing for American sprinter Tyson Gay. He got hurt prior to Beijing in 2008 and was trying to earn his first Olympic medal. Instead he finished fourth.

The semifinals were also run earlier on Sunday. The only surprises were Justyn Warner's failure to qualify and Keston Bledman's inability to do the same. For full semifinal results, click here.

View full finals results here.

Gold: Usain Bolt, Jamaica

Silver: Yohan Blake, Jamaica

Bronze: Justin Gatlin, USA

The men's steeplechase isn't for the faint of heart, but only two athletes failed to finish on Sunday. Kenya claimed two of the top three spots and three of the top five overall.

Team USA's representatives, Evan Jager and Donn Cabral, finished sixth and eighth, but they were a long way off of the leaders.

Less than two seconds separated the medal winners in this race. It was a dash to the finish, but Ezekiel Kemboi claimed the coveted gold medal.

View full results here.

Gold: Ezekiel Kemboi, Kenya

Silver: Mahiedine Mekhissi-Benabbad, France

Bronze: Abel Kiprop Mutai, Kenya

Sanya Richards-Ross did exactly what she came to London for on Sunday. Richards-Ross won Olympic gold in the women's 400-meter race, one of two Americans to earn a medal.

Richards-Ross' victory was expected. She won by .15 seconds and was the best athlete for the duration of the lap. It's an incredibly tough race to run, but she mastered it.

Dee Dee Trotter also earned a medal for Team USA. Her bronze performance was two one-hundredths of a second from earning her a silver.

View full results here.

Gold: Sanya Richards-Ross, USA

Silver: Christine Ohuruogu, Great Britain

Bronze: Dee Dee Trotter, USA

The eight participants in the men's 400 final have been determined. No Team USA member made the cut, with Bryshon Nellum's 45.02-second run not being quite enough to qualify.

Lalonde Gordon and Kirani James were the top two qualifiers. Gordon won Heat 1 with a 44.58-second run. James won Heat 2 with a 44.59. Watching their battle in Monday's final will be interesting, but others will contend as well.

Keep an eye on the Bahamas' Chris Brown in the final. He finished behind James in Heat 2, but he closed very strong.

Another story to keep an eye on is the Borlee brothers. Both qualified for the final for Belarus.

View full results here.

Qualifiers

Lalonde Gordon, Trinidad

Demetrius Pinder, Bahamas

Steven Solomon, Australia

Kirani James, Grenada

Chris Brown, Bahamas

Jonathan Borlee, Belarus

Luguelin Santos, Dominican Republic

Kevin Borlee, Belarus

Krisztian Pars won the gold medal in the hammer throw on Sunday with his 80.59-meter (264'1") throw. He finished fourth in Beijing, so this redemption must feel good for him.

Finishing behind him were Primoz Kozmus and Koji Murofushi. Both finished within two meters of Pars, but neither had enough to claim the ultimate prize.

Team USA's representative Johnson Kibwe finished in ninth place with a 74.95 (245" 10')-meter throw.

View full results here.

Gold: Krisztian Pars, Hungary

Silver: Primoz Kozmus, Slovakia

Bronze: Koji Murofushi, Japan

Heat 1 and Heat 2 were two very different occasions in Sunday's men's 1500-meter semifinals. Taoufik Makhloufi won Heat 1 with 3 minutes, 42.24 seconds, and Abdalaati Iguider won Heat 2 with a 3:33.99. Both runners had the privilege of winning, but it's obvious who was better in this round.

Two Americans, Leo Manzano and Matt Centrowitz, qualified for Tuesday's final with solid runs. They didn't finish near the top of the field, but they will be within striking distance in the final.

Andrew Baddeley failed to qualify for Great Britain in Heat 2. It's disappointing for the British squad, as he was their only representative in this event.

View full semifinal results here.

The women's triple jump has run its course in London and medal winners have been crowned.

Olga Rypakova won the gold medal after qualifying as the No. 1 contender on Friday. She finished fourth in Beijing, and this medal is excellent redemption for a world-class competitor. She jumped 14.98 meters or 49' 1.75" to win the Olympic gold.

This year's medalists finished nearly 0.25 meters, or 10 inches, further than the rest of the competition. They were obviously this year's best, and their performances warranted the medals they earned.

View full results here.

Gold: Olga Rypakova, Kazakhstan

Silver: Caterine Ibarguen, Colombia

Bronze: Olha Saladuha, Ukraine

The men's high-jumping qualification has begun, and the final will commence on Tuesday. The jumpers on Sunday, if preliminary jumps are any indicator, will put on a show.

Six jumpers qualified with a 2.29-meter (7' 6") jump, while the rest of Sunday's best jumpers finished with a 2.26 (7' 5")-meter jump. Anything lower than those marks failed to qualify for London's final.

Keep an eye on American jumper Jamie Nieto on Tuesday. He didn't qualify for Beijing's games, but he had a solid showing in Athens in 2004.

View full results here.

The first round of the women's 400-meter hurdles qualifying got underway on Sunday. The semifinals will take place on Monday, but this is the first step in determining this year's 400 hurdles champion.

There weren't any major surprises from Sunday's Round 1 action. Georganne Moline ran the fastest qualifying time overall for Team USA and won Heat 4, but Natalya Antyukh looked stronger with her 53.90-second run in Heat 2.

Look at the full list of participants and who qualified here.

The women's marathon came down to the quick (as you can see in the picture). Four women finished within one second of each other, with two more nipping at their heels.

Tiki Gelana won the race with an Olympic-record time of 2:23.07. Priscah Jeptoo finished with a 2:23.12 to earn a silver medal.

Team USA wasn't expected to medal in this race, and they didn't. Shalane Flanagan finished 10th, and Kara Goucher finished 11th. Desiree Davila didn't finish.

As expected, Kenya performed very well. They finished with two runners in the top five and another in the top 20.

A marathon doesn't make you think "exciting finish," but this one was different. Watching the leaders plow toward the finish of an epic race was truly fun to watch.

View full marathon results here.

Gold: Tiki Gelana, Ethiopia

Silver: Priscah Jeptoo, Kenya

Bronze: Tatyana Petrova Arkhipova, Russia