Tiebreaks may give John Isner grey hair, but they usually give his opponents heart attacks.

Two tiebreaks were enough to give the American his second Heineken Open in Auckland on Saturday, as he used his dominant serve to beat a gallant Yen-Hsun Lu 7-6 7-6.

In four matches in Auckland this week, third seeded Isner played 11 sets. Seven went to tiebreaks, and the only one he lost was in a 6-7 7-6 7-6 quarter-final win over Philipp Kohlschreiber.

Isner couldn’t convert any of his 10 break points against Lu and he fell a mini-break behind in the second set tiebreak. But ultimately the man whose 64.6 per cent career percentage for tiebreak wins is second only to Roger Federer proved too strong.

“I wish it didn’t have to be so close at the end – it gives me a lot of grey hairs – but I’m so happy to have won the tournament,” he said.

The tiebreak format undoubtedly helps a player like Isner who can get free points with his big serve, but it’s also a situation where the adrenaline helps him up his game.

“When I’m serving a regular game I could probably afford to lose a point here and there, but when I’m in a tiebreaker, sometimes I can’t. I normally serve my best in that situation and it puts a lot of pressure on my opponent.”

It was Isner’s eighth tournament victory, but his two wins in Auckland are his only titles outside the United States.

“I feel super-comfortable here. People here are so nice, the food is great, the city’s amazing, people speak English – that helps. I don’t feel like I’m so far away from home.”

The unseeded Lu, ranked 48 places below Isner at 62, said he was happy with the way he played, barring one volley which gave Isner the match point he finally took.

“He just served incredible. I couldn’t read his serve, and even sometimes when I guessed right I couldn’t get the ball back.”