Aldrich Bailey and Olivia Ekponé each ran second leg on their respective 4 x 400 relays as the United States claimed two gold medals and completed a sweep of the relay events at the World Juniors.
In the women's discus Shelbi Vaughan tossed the platter 197 feet, 1 inch (60.07) to finish third behind a pair of German throwers. Vaughan took over the lead twice in the competition, in rounds two (58.46) and four 197-1.
Round six had both German throwers passing Vaughan to snare gold and silver with marks of 204-8 (62.38) and 198-2 (60.42). Vaughan, who fouled three times, finished the day with a 192-8 (58.72) in the final stanza.
"I'm excited," said Vaughan. "I wish I could have gotten a further throw out there, and I was looking to place higher than third because that's where I finished last year in the World Youth Championships. But, third in the world - can't complain.
"I was excited to hit 60 (meters) because it is close to my personal best. I was really hoping to get another PB, but it didn't happen today. I'm still the youngest of these girls that made the finals, so I'm pleased."
The women's 4 x 400 relay team had to rerun its semifinal race after they protested a disqualification from the previous day. They clocked 3:34.25 to become the ninth team in the final.
Starting in lane nine the Americans controlled the race from the opening leg. Ekponé increased the U.S. lead on her second leg carry.
While Jamaica challenged on the third leg, the American squad closed out the 3:30.01 victory with NCAA champion Ashley Spencer of Illinois on anchor leg. Jamaica finished second in 3:32.97 with Russia third in 3:36.42.
Bailey also placed the United States men's team in solid position with his second leg carry. The American squad rolled to a 3:03.99 victory over Poland (3:05.05) and Trinidad (3:06.32).
"This was great, but kind of sad that it's over," said Bailey, who earned a gold medal with the 4 x 100 relay and an individual bronze in the 400m. "Now, when I get back home, I'm going to miss the team. This was fun, and it was worth it. I'll do it all over again.
"We did well as a team. We just wanted to come out and represent the United States. I came out of here with three medals, so I can't be mad."
Aggie recap at the World Junior Championships
Gold: Aldrich Bailey, 4 x 100
Gold: Aldrich Bailey, 4 x 400
Gold: Olivia Ekponé, 4 x 400
Gold: Jennifer Madu, 4 x 100
Silver: Olivia Ekponé, 200m
Bronze: Aldrich Bailey, 400m
Bronze: Shelbi Vaughan, discus
5th: Jennifer Madu, 100m
7th: Dalton Rowan, discus
Semifinal: Gregory Coleman, 400 hurdles
Qualifying: Devin Bogert, javelin
Qualifying: Jennifer Madu, triple jump