Possible Clues:

• Close-run thing featured in glossy, perhaps?
• Horse in cup close to Teenoso, snapper perhaps captures in — this?
• Glossy or matte, e.g.
• Narrow victory, or a feature of 17-, 29- and 47-Across
• In which officialdom must make a snap decision for the better
• Close ending to a race
• Very close ending
• Need for a close race in the maze?
• In which some are on course for a snap decision?
• Virtual dead heat in a horse race