That growth had massively outstripped the 5.5% increase seen in the wine market as a whole, said trading controller Laura Jewell, and its November sales compared with the same month last year were even better still up 24%, with Spar-branded wines up 56%.
Sales had been boosted by a half-price Champagne offer during the month.
Since joining the company in May, Jewell, who is a Master of Wine, has added new own-label wines and improved branding by putting more descriptions on the front of bottles.
"We are outperforming the market," she said. "We have had a very strong promotional programme and we are in the middle of a complete redesign of the Spar-branded wine."
Jewell expects Spar's wine sales to keep growing next year when she carries out a full range review.
The demise of Threshers-owner FQR would also be an opportunity for Spar stores to sell more wine, she added.
Meanwhile, Spar reported total sales growth of 8% and like-for-like sales of 4.8% in the 13 weeks to the end of October. Confectionery was the best-performing category with sales up 10%, helped by the collapse of Woolies.