Rafael Nadal has progressed to the quarter-finals of the Qatar Open with victory over Tobias Kamke in the second round.
The world number one got the better of his opponent 6-3 6-7(3) 6-3 to set up a clash with seventh seed Ernests Gulbis in the last eight.
Nadal eased to a 6-3 win in the first set, but was 4-1 down at one stage in the second.
However, the Spaniard recovered to take it to a tie-break, which Kamke won 7-3 after surviving three break points.
The 27-year-old regained his composure in the third and decisive set to win it 6-3 and avoid an upset.
