Jason Lambert (23-8) and Jason Day (17-7) will meet inside the Octagon at UFC 88: "Breakthrough" at the Philips Arena in Atlanta, Ga., on September 6.
MMAmania.com was able to independently confirm the booking, which was originally posted over at FiveOuncesOfPain.com.
"The Punisher" appears to be making the drop to middleweight after competing most of his career in the heavyweight and light heavyweight divisions. Perhaps back-to-back losses to 205-pounders Wilson Gouveia and Luis Arthur Cane, respectively, convinced Lambert to try his luck in the 185-pound division.
Lambert has three losses in his last five attempts within the eight-sided cage.
Day was victorious in his debut for the promotion against Alan Belcher at UFC 83: "Serra vs. St. Pierre 2" in April, upending Alan Belcher via first round technical knockout. The Canadian product was then stopped himself in the same fashion less than two months later when he locked horns with Michael Bisping at UFC 85: "Bedlam."
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