New England had its six-game home winning streak snapped, while San Jose ended a five-game road losing streak.
Cropper had a great reaction save of Fatai Alashe's redirection in the 66th minute. Cropper was moving to his right but extended his left leg to deny a near-post shot.
Cropper also punched away Darwin Ceren's blast in the 88th minute.
San Jose goalkeeper David Bingham also had his second clean sheet of the season. He came out of his area to deny Diego Fagundez in the 26th minute. Fagundez had a nice give-and-go with Juan Agudelo in the 74th, but Fagundez's rolling shot was knocked wide by Bingham.