Alexander Zverev's superior serving led to a 6-4 3-6 6-3 win over Borna Coric at the Miami Open on Friday as the tournament's second seed punched his ticket to the third round.
The towering German, who came into the match with a losing record against the Croatian, served his way out of trouble in the first game of the third set and fended off a break point while serving up 5-3 en route to the hard-fought win.
Zverev, who crushed 12 aces and only committed one double fault, said his more aggressive approach was the difference in the contest.
"The last few matches I was losing close three-set matches because I felt I wasn't going for it," said Zverev, who fell to Tommy Paul in a tight three setter in the second round of Indian Wells earlier this month.
"Today I felt like if I'm going to lose, I'm going to go for it. That worked out and hopefully it will in the next match as well."
Zverev said he will have his hands full when he faces either American Mackenzie McDonald or Bulgarian Grigor Dimitrov in the third round.
"Grigor is playing extremely well right now. He made the quarter-finals at Indian Wells, playing at an extremely high level, but Mackie is good on the fast surfaces, which it is here," he said.
Elsewhere in second round action, Italy's ninth seed Jannik Sinner beat Emil Ruusuvuori of Finland in the best match of the tournament so far, rifling a forehand service return winner to seal a 6-4 3-6 7-6(8) victory.
World number 11 Sinner will next face Pablo Carreno Busta, who beat David Goffin of Belgium 6-3 6-2.
Frenchman Hugo Gaston overcame 22 aces from American John Isner to advance 7-6(5) 6-4 and 10th seed Cameron Norrie came out on the winning side of an all British battle with Jack Draper 7-6(5) 6-4 at the Masters 1000 tournament.
