Michael Phelps waits to receive his gold medal after the 200-meter butterfly final. (Ezra Shaw/GETTY IMAGES)

Michael Phelps stared up the scoreboard Wednesday night, digested the result, then raised his index finger and shook it gently. He might not be as strong as he was in 2008. He might be a work in progress. But at least he is still No. 1 in something.

That would be the 200-meter butterfly, the event he dominated for the last decade — until this year. He lost for the first time in nine years and some 60 races back in April. And then he lost again. And then again.

Phelps ended that humbling three-race losing streak by extending a far more impressive one: He earned his fifth world title in the event.

A day after letting fellow American Ryan Lochte overtake him in the 200 freestyle final at the swimming world championships, Phelps showed the will and late-race stamina that have been his trademark to claim the gold medal 10 years after winning his first world championship at age 16. He overtook Japan’s Takeshi Matsuda over the last 50 while holding off China’s Wu Peng.

“I didn’t want to lose that race again,” Phelps said. “Having a number of defeats this year, that was extremely frustrating for me. I didn’t like that feeling. I kind of wanted to have the feeling of winning a race again.”

Phelps, the 14-time Olympic gold medal winner, touched the wall in 1 minute 53.34 seconds. Matsuda finished in 1:54.01. Wu, who had scored two of the victories over Phelps, came home in 1:54.67, disappointing the crowd at the Oriental Sports Center that had drowned out the announcement of his name before the race’s start.

“I hope I can achieve better results in London” at the 2012 Summer Games, Wu said.

At his training home at the North Baltimore Aquatic Club, Phelps often stares at a giant picture of himself from 2001, when he won his first world title in Fukuoka, Japan. His race winning streak began a year later, after he lost by 0.2 of a second to Tom Malchow at that year’s Pan Pacific Championships.

“I always look at myself in that picture and think I look so young,” Phelps said. “I was kind of young.”

He won his second world title in Barcelona in 2003, when, among other achievements, he set two world records in two different events on the same day. He did not compete in the 200 fly at the 2005 world championships in Montreal; two years later in Melbourne, he not only won his third 200 fly world title but broke his world record in the event by 1.62 seconds. At Rome two years ago, he broke the world record again.

“It may not always be a fun event,” Phelps said, “but it’s something I’ve built my whole career off of.”

And it seemed in jeopardy before Wednesday’s final. Phelps had failed in his first two bids to earn gold medals at these championships, claiming a bronze with the 4x100 freestyle relay team and a silver in the men’s 200 freestyle, where he had been overtaken in the second half of the race by U.S. teammate Lochte.

And he had suffered the three defeats that his coach, Bob Bowman, called “the definitive wakeup call.” The first, in Ann Arbor, Mich., to Wu, provided the biggest shock. The second came in Charlotte in May when Wu topped him again; Phelps faltered in the last 50, running out of energy. The third came weeks later in Santa Clara, Calif., to Australian Nick D’Arcy.

Phelps went out fast Wednesday, hoping to get far enough ahead to resist any late challenges. He said he considered Matsuda, a great finisher, the biggest threat in the field. Matsuda trailed for the first 100 meters but passed Phelps before the final wall.

“I had a chance to win against Michael Phelps, and I didn’t win,” Matsuda said through an interpreter. “In the end, I felt a bit regretful. . . . In the last 50 meters, [I] was very tired. [I] could feel that Michael Phelps was catching up.”

Phelps came hard, swimming the final 50 in under 30 seconds — the only swimmer in the field to do so.

“I didn’t really work the underwaters like I should have, because I was trying to save up my legs for the last 50,” Phelps said. “I dug as deep as I could the last 50 . . . I tried to put it in the biggest overgear I could put it in, and just get to the wall.”

After accepting his medal and posing for a few photos, Phelps sprinted toward the aquatic center’s underbelly to prepare for another race, a semifinal of the 200 individual medley. Phelps easily advanced to Thursday’s final with the second-best time: 1:57.26. Lochte topped the night’s swimmers with a time of 1:56.74.

Phelps said he wanted to keep his emotions under control, knowing he had more work to do at this meet. And the margin of victory left him as wary as excited.

“I still want more in that event,” Phelps said. “I want to be faster. That was a little too close for comfort. . . . This is just a small step for my next year.”