DOHA (REUTERS) - Roger Federer's hopes of winning a fourth title in Qatar were dashed after Thursday's quarter-final exit but the Swiss said his first event after two knee surgeries was just a "stepping stone" as he targeted full fitness for the grasscourt season.

Federer took the opening set against Nikoloz Basilashvili before the Georgian fought back to win 3-6 6-1 7-5, ending the 39-year-old Swiss' challenge at the tournament - his first event in 14 months.

"I'm actually happy that I was able to play back-to-back three-set matches against top players. That's an important step forward to me," Federer, who beat Dan Evans in the last-16, told reporters.

"Like I said, I'm not 100 per cent yet. I can feel it, I can see it. From that standpoint, (what's) important is to be 100 per cent by the grasscourt season... I'm still building up.

"So this is a stepping stone. I'm actually happy how I felt today on court overall."

Federer initially eyed a return at last month's Australian Open but slow progress in his recovery convinced him to skip the Grand Slam and he said he would play in events which would help him regain his fitness before Wimbledon.

Tied with Rafa Nadal on 20 Grand Slam wins, Federer has won Wimbledon eight times.

"We've just got to take a real good look at the schedule and... see how much workload the body and knee can still take, what's the best way to prepare for basically the beginning of the season for me, which is the grasscourt season," he added.

Federer also said he had not yet decided if he would play in Dubai, an ATP 500 event which begins on Sunday.

"I'll decide probably in the next 24 hours," he said.