Christian Yelich's mom knocked house hunting for her son out of the park ... 'cause she just helped the Milwaukee Brewers star score a $5.6 MILLION beach house in Malibu!!
Alecia Yelich repped her baby boy -- a 26-year-old outfielder -- in the house hunt ... and got $400,000 knocked off the original listing price of $6 mil ... and the house is sick.
It's a 2,500-square-foot pad -- listed by Cormac and Wailani O’Herlihy from Sotheby’s -- right on the beach off the Pacific Coast Highway in the 'Bu ... and features its own elevator, roof-top patio and wet bar.
No word yet on what Christian owes mom for the assist ... but we're betting one of the house's three bedrooms is hers.