Is the bloom off the Jeep Grand Cherokee’s rose?

As Chrysler extends to 18 its run of monthly year-over-year U.S. sales gains, the celebrated SUV saw its streak stopped at 12.

Deliveries of the redesigned-for-’11 Grand Cherokee totaled 10,580 in September, a 3.1% dip compared with like-2010, marking the first time the nameplate has seen the red since recording a 13.4% shortfall in August 2010, according to WardsAuto data.

Chrysler sales climbed 27.1% last month on 126,721 deliveries, besting Toyota for the fourth time in five months.

Through September, the auto maker’s tally was up 22.9% on 1,004,123 unit-sales. Chrysler did not eclipse the million mark last year until December.

Last month’s Grand Cherokee setback had little impact on Jeep’s overall performance. Of models still in production, the Grand Cherokee was the only one in negative sales territory for the month.

Through June, the SUV outpaced the brand’s longtime volume leader, the Wrangler. But through September, Grand Cherokee sales totaled 85,769, tracking 78% ahead of like-2010.

Led by 11,388 Wrangler deliveries, Jeep’s September tally was 35,565, a 24.3% jump compared with prior-year.

The Jeep Compass, beneficiary of a significant facelift this year, accounted for 4,422 deliveries in September, more than triple its like-2010 total.

On a percentage basis, other September winners in the Chrysler lineup included:

Chrysler sales chief Reid Bigland says in a statement the auto maker recorded a 50% hike in retail sales last month.

“There is no double-dip downturn going on around here,” says Bigland, who also leads Dodge as brand president and CEO.

The Dodge Charger, a 300 platform-mate, arguably was the biggest loser in Chrysler showrooms. Its September sales plunged 22.9% compared with like-2010, according to WardsAuto data.

The only vehicles faring worse, on a percentage basis, were out-of-production models and those scheduled to end their runs this year, such as the Dodge Caliber C-car.

WardsAuto data is adjusted for sales days, of which there were 25 both last month and in September 2010.