DES MOINES, Iowa — Mentally, Tyson Gay is now in a good place. Physically, too.

That's the healing power of running fast at nationals.

Once and for all, Gay, a former Barton Community College star track and field athlete, put to rest any questions about his surgically repaired hip as he completed the 100-200 sprint double Sunday at the U.S. track championships, winning the 200 meters in 19.74 seconds.

It is the fastest time in the world this season. Gay also beat Justin Gatlin in the 100 on Friday in a season-leading time of 9.75.

"I'm pretty tired," Gay said. "I'm just glad I'm leaving the race healthy."

With his strong performance, Gay delivered an emphatic message to the rest of the world, and more specifically Usain Bolt: The Gay of old is back. Not the version hobbled by nagging injuries over the years, but the one who captured the 100 and 200 titles at the 2007 world championships.

"I'm just happy to be healthy," Gay said. "It feels good, man."

It should be quite a show when he meets up with Bolt at worlds in Moscow in August. Not that Gay is thinking any farther than icing down his legs after an exhausting weekend.

"I'm just focused on myself right now," Gay said. "It's no secret Usain Bolt is obviously the greatest of all time. He's definitely going to be prepared."

In the women's 200, Kimberlyn Duncan upset Olympic champion Allyson Felix. Duncan finished in a wind-aided 21.80, with Felix 0.05 seconds behind. Jeneba Tarmoh was third.

Felix said she got a late start on training and hasn't completely found her racing form yet. She skipped the 100 earlier in the week to be more prepared for her signature event, the 200.

"I'm lacking a little bit of speed right now," Felix said. "Overall, my conditioning could be a little better."

Still, Duncan did something in this race that few have done to Felix — made up ground and blazed by her at the finish.

"I didn't know what to do. I was overjoyed," said the 21-year-old Duncan, who won three straight NCAA 200 outdoor titles at LSU. "I'll take that time, windy or not."

It was a busy day to finish nationals, with one final after another in rapid succession. Other winners included Alysia Montano (800), Jennifer Simpson (5,000), Duane Solomon (men's 800), Ryan Wilson (110 hurdles), Bernard Lagat (5,000), Erik Kynard (high jump), Riley Dolezal (javelin), Evan Jager (3,000 steeplechase), Dalilah Muhammad (400 hurdles), George Kitchens (long jump), Ryan Whiting (shot put), Gia Lewis-Smallwood (discus) and Tim Seaman (20,000 race walk).

Olympic pole vault champion and indoor record holder Jenn Suhr cruised to a national title, setting up a showdown with outdoor record holder Yelena Isinbayeva of Russia.

In Isinbayeva's backyard, no less.

"I'm inviting as many family members that will go over to Moscow as I can to help cheer for me," Suhr said. "I think I might be the underdog there. We're hoping to get a big crowd over there."

Before climbing into the blocks for the 200 final, Gay took two big breaths, stretched his hip and sipped on some water. When the gun sounded, Gay flew out of the blocks and built up a sizable lead after the curve — just like Gay used to do.

His work wasn't done, though, as he had to fend off the hard-charging Isiah Young, who finished second in 19.86. Curtis Mitchell, the training partner of Gay, was third to grab the last spot in the 200, while Wallace Spearmon, a three-time U.S. outdoor champion, wound up a disappointing fourth.

"You win some, you lose some, and I lost today," Spearmon said. "Congratulations to those guys. No excuses. I'm going to go home and work hard."

To think, Gay almost skipped the 200. Given his recent history with his hip, Gay didn't want to tax it too much, and that win over Gatlin in the 100 definitely took a lot out of him.

The morning after the 100 race, the hip felt just fine, so he elected to run the opening 200 heat on Saturday. That night, Gay had an ultrasound on his hip, to see where the scar tissue was and then have it worked on.

"That worked out well for me," Gay said.

Certainly did. This was his fastest 200 in quite some time.

"It does help me mentally, to get ready for Moscow," Gay said.

There was a little dispute, though, as some questioned whether or not Gay stepped out of his lane in a semifinal heat Sunday afternoon. He advanced to the final, and afterward dismissed such speculation.

"Someone may have mentioned it to me, but I didn't pay any attention," Gay said.

With that, he will double at worlds, feeling as good as he has in a long time.

"Tyson was very impressive. I'm glad to see it," former Olympic champion Maurice Greene said. "I know what he's went through, because I've talked to him numerous times on the phone, been to his house. I've talked to him for hours and hours. I know how he feels. To finally come back and be healthy, I'm so proud of him."

In the final race to close out nationals, Wilson held off a competitive field in the hurdles. David Oliver was second, and Olympic champion Aries Merritt finished third. Jason Richardson wound up fourth, but he has an automatic spot at worlds by virtue of his win in 2011.

"Very, very rusty," said Merritt, who has been dealing with a balky hamstring. "But the main objective was to qualify, and I punched my ticket."