It's the second week of the London Games, which means track and field is in full swing at Olympic Stadium.
The first medals on the track have already been awarded, and now the heats for some of the biggest races are in full swing.
Already, there have been major upsets on the track, inspiring stories and, not to mention, some outstanding times.
So let's take a look at the early winners and losers from the first day of track competition.
The first event to take place on the track is perhaps the most grueling, but Ethiopia's Tirunesh Dibaba fought through the pain to capture gold in the 10,000-meter race.
Dibaba won with a time of 30 minutes and 20.75 seconds, six seconds ahead of her nearest competitor—Sally Kipyego of Kenya—in the 25-lap race.
This was her second straight victory in the event, as she won gold in the 10,000 in Beijing. It's also her third gold medal—the most ever by a female distance runner.
She has one more chance at gold this Olympics in the 5,000-meter, where she will once again defend her crown in hopes of winning back-to-back titles twice in one Games.
If she does so, the 27-year-old would potentially establish herself as the best female distance runner of all time.
LeSawn Merritt entered the Olympics as the favorite to repeat his gold-medal performance from the 2008 Games.
Instead, he's headed home after the preliminaries.
Merritt pulled up in his qualifying heat on Saturday morning with a tender left hamstring—an injury he suffered in a tuneup race last month in Monaco.
This is especially disappointing for Merritt, as he was attempting to rebound from a 21-month drug suspension. A gold medal would have been the perfect cure.
Merritt hadn't lost a race in 2012, but the injury was just too much to deal with, even if it cost him his title defense, according to the Associated Press (via NBC Sports).
"It's very disappointing to ... be dealing with an issue and not be able to finish the race," Merritt said. "I'll regroup."
Oscar Pistorius could be having the best Olympics out of anyone.
Pistorius, a double amputee, finished second in his 400-meter qualifying heat on Saturday with a time of 45.44 seconds.
His second-place finish pushed him into the semifinal round of the 400—an incredible result for someone who was just thrilled to be there.
Pistorius’ appearance in the 400 made him the first Paralympian to ever compete in the able-bodied Olympics. Just a year ago, it looked as if he wouldn't even make it there.
The man known as the "Blade Runner" has been embroiled in controversy regarding whether his prosthetic legs give him an advantage on the track.
Ultimately, though, the IOC ruled in his favor.
When he finished second in qualifying at South Africa's Olympic trials, his Olympic dream had finally come true.
Now, that dream is a reality. And on Sunday, he has a chance to make it even more than that if he can find a way to sprint into the finals.