DOHA: Borna Coric beat second-seeded Pablo Carreno Busta 5-7, 6-2, 7-6 (8) in the first of a series of upsets at the Qatar Open on Tuesday.
The 48th-ranked Coric saved three match points in the third set tiebreaker before taking advantage of his lone match point when Carreno Busta netted a forehand to secure his place in the second round.
Coric successfully broke Carreno Busta's serve when the Spaniard was serving for the match at 5-4 and 6-5 in the third set.
The Croat won 27 of the 33 points he played at the net, and had 44 overall winners in the 2 hours, 42-minute match.
"I didn't know what to expect," Coric said. "It's the first match of the year. It's always maybe a little bit tricky, but I can say from the beginning that I was playing very good.
"In the offseason, I was working a lot on the net. I'm very happy with that stat."
The 10th-ranked Carreno Busta has won only one of nine official tour matches he's played since reaching the U.S. Open semifinals, where he lost to Kevin Anderson.
However, his defeat wasn't the only surprise on Tuesday.
Third-seeded Tomas Berdych of the Czech Republic and fourth-seeded Albert Ramos-Vinolas of Spain were also beaten in the first round.
Berdych lost 6-4, 1-6, 7-6 (4) to Jan-Lennard Struff of Germany, while Ramos-Vinolas was beaten 2-6, 7-5, 7-5 by Guido Pella of Argentina.
"Pretty tough match," the 53rd-ranked Struff said. "Very close. I know Tomas, he beat me in French Open. So I knew what to expect in the game.
"I played very aggressive in the tiebreaker and I was very happy after that one," Struff added.
Eighth-seeded Feliciano Lopez also advanced with a 6-4, 5-7, 7-6 (3) win over fellow Spaniard Guillermo Garcia-Lopez.