NEW YORK (CNN/Money) - Despite a wobbly start, shoppers pulled through in the end for retailers to deliver the strongest holiday season in five years, according to the National Retail Federation.

The NRF said Thursday that combined sales for the November- December shopping period grew 5.7 percent, the strongest growth since the 8.3 percent growth in holiday sales in 1999 and higher than last year's 5.1 percent increase.

NRF had been predicting sales for the two-month period to rise 4.5 percent.

"Even after all of the hand-wringing by retail analysts, the holiday season ended on strong footing," NRF chief economist Rosalind Wells said in a statement. "Post-holiday discounting and gift-card redemptions helped provide a last-minute surge in spending."

The group said December retail sales in the GAFS category (general merchandise stores, clothing, furniture, electronics and appliances stores, and sporting goods and other) jumped 6.4 percent over the previous year.

Among the strong performers, furniture and home furnishings stores saw solid gains, with sales up 2.2 percent from November and rising 7.2 percent over 2003, the NRF said.

General merchandise stores, which include department stores, grew 0.7 percent from the prior month and 7.8 percent over the previous year.

Sales at sporting goods stores rose 0.9 percent from November and 4.2 percent over 2003, while clothing sales slipped 0.6 percent from November but saw a 5 jump percent over the previous year, the group said.

"It looked like a very good holiday for retailers afterall," said Richard Hastings, retail economist with Variant Research. "Similar to last year, there was an erratic streak with shopping trends strong at the outset and then tapering off to pick up again closer to Christmas."

Going forward, Hastings said he's more concerned about the macro-economic trends than the steep year-over-year comparable sales comparisons retailers face in the first-quarter.

"Oil prices are rising, Iraq instability continues and there's a market correction taking place," he said, adding that these are factors that could curtail consumer spending.