Shares in the retailer leapt eight per cent after it agreed on a deal to sell loss-making gaming arm Multiplay for £19m.
Sports Direct bought a 25.75 per cent stake in Game in July. Over the summer, Game's stock market valuation was languishing at its lowest point since floating in mid-2014. Since Ashley invested shares have almost doubled, meaning his stake in the firm has increased from £10m to £20m.
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Game boss Martyn Gibbs said the Multiplay transaction represented a "significant strategic step forward" for the London-listed firm.
Two weeks ago Game said the tide had turned for the retailer, boosted by a resurgence in popularity of the Nintendo Switch, Gibbs said: "After two years of declines, our core UK console market returned to growth."
After a spectacular crash in 2008, Nintendo shares have surged with stock market valuation of the Japanese firm doubling during 2017.
Today, Gibbs said: "By divesting Multiplay Digital we simplify the Group and focus management on accelerating development plans to fully capitalise on the strong growth potential in our exciting and growing esports activities."