By Matt Smith

DOHA (Reuters) - World number three Roger Federer vanquished Slovenia's Grega Zemlja 6-2 6-3 in the second round of the Qatar Open Wednesday to rack up his 19th successive victory.

The Swiss laid down his title credentials for the Australian Open later this month with yet another quickfire victory and has now dropped just nine games in two matches in Doha.

"The year-end was very short. I'm trying to maintain my level and carry it on in 2012," the 16-times grand slam champion said in a court-side interview.

Against Zemlja, Federer lost just 11 points on serve and converted half of his six break points.

He sprinted to a 3-1 lead and after overcoming a minor hiccup in the seventh game, when Zemlja hit a crosscourt winner to earn a break point, Federer clinched the set with a sizzling backhand winner that left a flailing Zemlja stranded in mid-court.

Federer, 30, was nearly as dominant in the second, although Zemlja dug in to hold his first three services before Federer broke to take a 5-3 lead.

The Swiss clinched victory with a deep return that Zemlja could only scuff into the net, winning 12 of the last 14 points.

(Reporting by Matt Smith)