Enzyme with hydroxy-pyruvate reductase, glyoxylate reductase and D-glycerate dehydrogenase enzymatic activities. Reduces hydroxypyruvate to D-glycerate, glyoxylate to glycolate, oxidizes D- glycerate to hydroxypyruvate. {ECO:0000269|PubMed:10484776, ECO:0000269|PubMed:10524214}. This is the function of GRHPR (glyoxylate and hydroxypyruvate reductase, Ensembl gene identifier ENSG00000137106).