Lehmann initially signalled an intention to continue in his role after Steve Smith, David Warner and Cameron Bancroft were sent home from South Africa in disgrace for their roles in a pre-meditated plan that saw the latter attempt to alter the condition of the ball during the third Test in Cape Town.
Smith and Warner - formerly the captain and vice-captain of the team - were banned for 12 months by Cricket Australia (CA) on Wednesday, while Bancroft earned a nine-month suspension.
Twenty-four hours later, a tearful Lehmann - who was cleared of any wrongdoing by the CA investigation - confirmed he would leave his position in a news conference.
BREAKING: Darren Lehmann announces this will be his last Test as he is stepping down from his role as head coach pic.twitter.com/VZEKbS6ZZc
— cricket.com.au (@CricketAus) March 29, 2018
"It is the right time to step away," Lehmann told reporters, only a few hours after a "devastated" Smith had spoken of his remorse in an emotional press conference on his arrival back in Sydney.
"I hope the team rebuilds and the Australian public can forgive the young men and get behind the XI.
"Speaking to the players and saying goodbye was the toughest thing I've ever had to do.
"This was entirely my decision. I have been speaking to the hierarchy in the last couple of days."
Lehmann, who was contracted until the end of the 2019 Ashes, has led Australia for almost five years, having succeeded Mickey Arthur as coach just weeks before the 2013 Test series in England.
Although Australia lost that rubber, they soon regained the Ashes in emphatic fashion with a 5-0 whitewash of England on home soil. The most recent contest between the two teams was also dominated by Australia, who ran out 4-0 winners to again regain the urn following an away defeat in 2015.
In addition to a number of notable Test wins, Lehmann oversaw success in the 50-over format when his side won the 2015 Cricket World Cup.
Photo Getty Images. Caption: Australia coach Darren Lehmann