Michael Phelps and Ryan Lochte did their part.
The longtime rivals are headed to another showdown at the U.S. Olympic swimming trials.
Phelps and Lochte cruised through the semifinals of the 200-meter individual medley Thursday night, each of them winning their heats in dominating fashion.
"It means a lot," Lochte said. "I've been racing him in this event since like 2003. He's a tough competitor. I just love racing against him because it's a challenge."
This one is especially significant for Lochte, an 11-time Olympic medalist who has yet to qualify for an individual event in Rio.
Slowed by a groin injury, the 31-year-old Lochte missed out in the 400 IM — a race he won at the Olympics four years ago — finished fourth in the 200 freestyle, and dropped out of the 200 backstroke.
Though also entered in the 100 butterfly, Lochte is basically putting all his hopes on the 200 IM. A top-two finish will give him that cherished spot, but he really wants a win over Phelps in Friday night's final before they head to the Olympics.
"I'm feeling better as far as like mentally, but physically I'm getting tired," said Lochte, who at the very least will be going to Rio as a relay swimmer. "Tomorrow night will definitely be a good battle between me and Michael."
Lochte was the top qualifier at 1 minute, 56.71 seconds, while Phelps took the second spot in 1:57.61. That means they'll be right beside each other in the final, just as they've been so many times during their dazzling careers.
Phelps has already qualified for Rio in the 200 fly, but the most decorated athlete in Olympic history is eager to add two more individual races to his program. He'll be a big favorite in the 100 fly, a race in which Lochte doesn't figure to be a major threat.
This is their only real chance to race.
"Him and I have gone back and forth a number of times in this race," Phelps said. "During the big meets, we have great races. We're right there with each other tomorrow in the middle of the pool, probably a couple of tenths apart. We're going to be out and probably step on the gas a little bit more than we have in the past and you'll have an exciting race."
Missy Franklin, on the other hand, didn't even advance to the final of the 100 freestyle.
Another big star from London struggled to an 11th-place showing in the semifinals, leaving her with only one individual race in Rio and just one more chance to bulk up her program: the 200 backstroke.
No matter what, Franklin's bubbly personality will be much less of a presence at these Summer Games than it was four years ago.
"That speed just doesn't feel like it's quite there this meet," she said. "No idea why. It's super disappointing, but I really feel like my endurance is there, so it gives me a lot of hope for my 200 back."
While Franklin is struggling, another Olympic gold medalist will get a chance to defend his title.
Nathan Adrian, the burly 27-year-old who won the 100 freestyle in London, used a powerful finishing kick to win in 47.72 seconds. Caeleb Dressel will also get to swim the down-and-back sprint in Rio, taking the second spot at 48.23.
Anthony Ervin, the oldest swimmer at the trials, got off to a blistering start and led at the turn. The 35-year-old couldn't hold on, fading to fourth in 48.54 while also touching behind Ryan Held (48.26).
But the top four are assured of spots on the team for the 4x100 free relay, meaning Ervin will be headed to his third Olympics.
On the fifth night of the meet, Josh Prenot became the latest Olympic rookie to make the team, knocking off Kevin Cordes in the 200 breaststroke. Cordes had already won the 100 breast and was more than a second under world-record pace at the final turn of the longer race.
But Prenot, furiously bouncing up and down in the water, surged past Cordes on the final lap to win in 2 minutes, 7.17 seconds, setting an American record and finishing just off the world mark of 2:07.01 held since 2012 by Japan's Akhiro Yamaguchi.
Also Thursday, Cammile Adams won the 200 butterfly after being briefly disqualified once day earlier during the preliminaries. The ruling that she made an illegal turn was quickly overturned after a review provided by the underwater camera, and Adams took advantage of her second chance to win with a time of 2:06.80. Hali Flickinger took the second Olympic spot in 2:07.50.
Franklin is going to her second Summer Games, but she won't be nearly as busy this time around.
As a high schooler four years ago, Franklin took part in seven events, winning four golds and a bronze. At age 21, she's shaping up as one of the biggest flops of the trials, outside of a gutsy runner-up finish in the 200 free behind Katie Ledecky.
At the most, Franklin will only swim three events in Rio.
Phelps figures to be much busier. He's shooting to swim three individual races, and will likely be a part of all three relays.
Oh, and he celebrated his 31st birthday on Thursday.
"I have a bunch of friends here and my mom rented out a room, so we're all going to get together and have some food," Phelps said.
Then he'll turn his attention to a familiar foe.