Race Comment Explainer

Original comment with matches highlighted:

made virtually all, driven inside final furlong,

Matched phrases & meanings

Phrase	Meaning
Furlong	Unit of distance; one furlong is 1/8 of a mile (approx. 200 meters).
held on	The horse managed to maintain its lead and win the race by a narrow margin.
gamely	The ultimate descriptor for a horse that wins bravely and resolutely after a tough battle.

Summary

Unit of distance; one furlong is 1/8 of a mile (approx. 200 meters).
The horse managed to maintain its lead and win the race by a narrow margin.
The ultimate descriptor for a horse that wins bravely and resolutely after a tough battle.