Lombardi was 17 of 24 passing for 282 yards with an interception.
He carried it 10 times for 119 yards, including scoring runs of 64 and 18 yards in the fourth quarter. Lombardi's earlier 7-yard run gave Northern Illinois a 21-14 halftime lead. Harrison Waylee added 130 yards on the ground with a touchdown for Northern Illinois.
John Richardson kicked two short field goals to make it 27-14 early in the fourth. Freddie Brock and Elijah Barnwell each had a rushing touchdown for Maine.