The U.S. squad stands at 25-under-par 407 and is nine clear of Spain. The Spanish duo of Alvaro Quiros (69) and Alfredo Garcia (71) combined for a 4- under 140 and second place at 16-under-par 416.
Levin was 2 under par when he reached the par-5 11th. His ball was stuck in a palm tree, but he managed to make bogey.
'A bogey was pretty good there,' said Levin. 'I was still 2 under at the time and I birdied 15, 16 and 17 and finished strong.'
Moore, who won two USGA titles, the NCAA Individual Championship and the Western Amateur this season, was most impressed with his teammate's play on Saturday.
'I was ecstatic when I saw Spencer's score,' said Moore. 'I think we were ham- and-egging it pretty well. Spencer stepped it up and played a good round when we really needed it.'
The U.S. is now in spectacular position to win its third consecutive Eisenhower Trophy.
Sweden (138) is alone in third at 15-under-par 417. Canada (136), Switzerland (143) and Italy (140) are knotted in fourth place at 10-under-par 422.
The team from Wales shot an even-par 144 on Saturday and is alone in seventh at minus-nine. England (141) and Malaysia (138) are tied for eighth at 8-under-par 424.
Germany (142) and Denmark (139) share 10th at 7-under-par 425.