Doha, Jan 7 (IANS): Defending champion Rafael Nadal was ousted in the first round of the Qatar Open, losing to German qualifier Michael Berrer 6-1, 3-6, 4-6.

Nadal had three break points on Berrer's serve in the final game, but couldn't convert on those opportunities to draw the third set score even to 5-5 Tuesday, reports Xinhua.

The second seed just came back from an appendectomy in November and has yet to find his top form.

Berrer had never before beaten a top-five ranked player. The 34-year-old father of two has already announced he's retiring at the end of the year.

Also Tuesday, top seed Novak Djokovic eased past fellow Serbian Dusan Lajovic 6-2, 6-1 in just 59 minutes.

Djokovic withdrew from the Abu Dhabi exhibition final last week with the flu, but showed no lingering signs of illness against Lajovic.

Czech third seed Tomas Berdych also advanced to the second round with a 6-1, 6-4 win over Denis Istomin of Uzbekistan in 62 minutes.

Spaniard David Ferrer toiled to get past the first hurdle when the third seed beat Dutch qualifier Thiemo De Bakker 6-7 (4-7), 6-4, 6-3 in two hours, 18 minutes.

Jan-Lennard Struff produced another surprise of the day as he defeated fellow German and fifth seed Philipp Kohlschreiber 7-6 (7-3), 4-6, 6-1.