(CNN) -- A baseball arbitration board has thrown out the 50-game suspension handed down to Milwaukee Brewers outfielder Ryan Braun after the 2011 National League MVP challenged the results of a December drug test.
Thursday's decision marks the first successful appeal of a suspension under Major League Baseball's anti-drug policy. Braun hailed it as "the the first step in restoring my good name and reputation," but Major League Baseball said it "vehemently disagrees" with Thursday's decision.
The 28-year-old Braun led the Brewers to its first division title in three decades with a .332 batting average, 33 home runs and 111 runs batted in during the 2011 season. But he was slapped with the suspension in December after a drug test that the sports network ESPN, citing unidentified sources, said showed high levels of testosterone.
Braun said there were "highly unusual circumstances" that would show his innocence. The arbitration panel apparently agreed, voting 2-1 to overturn the suspension, according to the MLB Players Association.
In a brief statement, the players' union said the result would not be made public normally -- but all parties agreed to release the decision "given the particulars of this case."
With baseball teams heading for spring training, Braun said in a written statement that he was "very pleased and relieved by today's decision."
"I have been an open book, willing to share details from every aspect of my life as part of this investigation, because I have nothing to hide. I have passed over 25 drug tests in my career, including at least three in the past year," he said. He thanked the Brewers, fellow players and fans "who stuck by me and did not rush to judgment."
"This is not just about one person, but about all current and future players, and thankfully, today the process worked," Braun said.
MLB said drug testing is "essential to the integrity of our game," and that league officials "will exhaust all avenues in pursuit of the appropriate discipline" when a player tests positive for banned substances.
A third-party review is part of the process, Rob Manfred, MLB's executive vice president for labor relations, said in a statement on the Braun decision, and the leagues "have always respected that process."
However, he added, "Major League Baseball vehemently disagrees with the decision rendered today" by the panel, led by arbitrator Shyam Das.
CNN's David Close contributed to this report.