Brunner took a second caution in two minutes, leaving his team a man down with seven minutes left in the first half. The Crew, though, raced upfield late in the half, but goalkeeper
Yosgart Gutierrez charged out block a shot by Robbie Rogers, released clear by Alejandro Moreno's pass.
Marshall re-directed into his own net early in the second half, when he couldn't deal with Alejandro Vela's cross.
Crew coach Robert Warzycha replaced playmaker Guillermo Barros Schelotto
early in the second half., but his replacement Adam Moffat nor subsequent changes could impede a determined opponent.
Cruz Azul kept coming forward, and a seeming stumble by Lozano yielded a phantom penalty that Lozano converted.
Lozano struck again, unexpectedly, when he fired a low shot from the left side that took a sharp deflection off Marshall and
dropped past stranded keeper Will Hesmer, who took a pounding through no fault of his own.
Concacaf Champions League
Aug. 26 in Mexico City
Cruz Azul 5, Columbus 0.
Goals: Lozano 4, Nunez 9, own goal (Marshall) 47, Lozano 82, 92+.
Cruz Azul - Gutierrez, Chavez, Brown, Cervantes, Huiqui (Zeballos, 58), Lozano, Torrado, Riveros, Nunez (Lugo, 67) Vela (Hernandez, 63), Villa.
Columbus - Hesmer, Hejduk, Marshall, Brunner, Padula, Carroll, Pirro, Gaven, Rogers (Lenhart, 79), Moreno (Ekpo, 65), Schelotto (Moffatt, 54).
Referee: Oscar Moncada.