Doha - Second seed Pablo Carreno Busta of Spain crashed out of the Qatar Open in the first round beaten by rising Croatian star Borna Coric in three sets on Tuesday.
Coric saved three match points and came from a set behind to win in a final set tie-break 5-7, 6-2, 7-6 (10/8) to record a notable victory in an enthralling match lasting 2 hours 41 mins.
The 21-year-old Croat, who beat Andy Murray last year at the Madrid Open, described it as a "huge win".
"I think I played very good," he told reporters.
"I didn't know what to expect, it's the first match of the year, it's always a little bit tricky.
"But, I can say from the beginning that I was playing very good."
He added, however, that the win did not compare to beating Murray.
Coric is ranked 38 places lower than world No 10 Carreno Busta but said it was his aim to break into the world's top 20 this season.
"I think I can do it but I need to play very good for the whole season."
Coric had considerable success adopting a serve-and-volley approach and won 17 out of 21 points at the net in the deciding set.
Overall he hit 44 winners during the match.
He will play Nikoloz Basilashvili in the second round. The Georgian has won their previous two encounters.
The tournament's number three seed, Thomas Berdych was in action later.
The Czech is one of three former finalists in action on Tuesday, the others being Frenchmen Richard Gasquet and Gael Monfils.
Number one seed, Austria's Dominic Thiem, won his first round match in straight sets on Monday.