He's not yet back to Michael Phelps speed, but he's getting closer.

Michael Phelps tires quickly after competing in multiple events at meet

USA TODAY Sports reported that 18-time Olympic gold medalist Michael Phelps turned in his most impressive performance of his comeback from retirement Friday night, defeating rival Ryan Lochte by more than a second in winning the 100-meter butterfly event at the Bulldog Grand Slam in Athens, Ga.

Phelps finished in a time of 51.67 seconds, breaking the 52-second barrier, which he and his coach set as a goal before the race.

"Seeing 52.1 so many times was really frustrating, kind of annoying," Phelps said after the race. "I am very pleased with being able to go 51. In the grand scheme of things, it's just a small stepping stone toward hopefully going where we want to be."

Michael Phelps' comeback motivates Ryan Lochte to return to form after freak accident

Only a day earlier, The Associated Press reported that Phelps was upset that he was progressing slower than he had hoped.

Now, Phelps has some momentum to go along with fixing the mistakes he says he is still making.

"I would have liked to have the No. 1 time of the world," Phelps said, according to USA TODAY Sports. "I'm just long on the turn and could have had more momentum coming into the finish. But to go 51.6 ... I guess I can't really be too disappointed or too frustrated after that swim."

His time on Friday was the third-fasted in the world, USA TODAY Sports reported. The time also was less than a half-second off his gold medal-winning time of 51.21 seconds at the 2012 London Olympics. Lochte finished in 53.08 seconds.

Phelps is scheduled to race in the 100-meter backstroke today and the 100-meter freestyle on Sunday. He could meet up with Lochte in both those races.

Do you think Michael Phelps will be as dominant in the 2016 Summer Olympics in Rio de Janeiro as he has been the last two Summer Games? Comment below or tell us @SportsWN.