Spaniard Roberto Bautista Agut has won his second Auckland Classic tennis title in three years, holding off a Juan Martin del Potro fightback to take out the final in three sets.

The fifth-seeded Bautista Agut dominated Saturday’s first set, trumping del Potro with unerringly accurate groundstrokes, eventually winning 6-1 4-6 7-5.

Yet at 4-4 in the second set, something clicked for del Potro.

Previously struggling to handle Bautista Agut’s swiftness, he began to take the ascendancy with big serves and even bigger forehands.

Soon after, he secured the second set 6-4, breaking Bautista Agut at the business end, before the two players went blow-for-blow in the deciding set.

Having failed to serve an ace in the first set or hold serve, del Potro slammed nine aces in the following two sets and improved his first-serve rate.

But in the end, it was the world No.12 who blinked first.

Bautista Agut earned the championship-deciding break at 5-5 before overcoming del Potro’s best efforts to serve out the match and lift the trophy.

Across the match, he won four of five break points.

He won the Auckland title in 2016, and defeated Kiwi Michael Venus, American Steve Johnson, Jiri Vesely and Robin Haase on his way to this year’s final.

Both players will head to Melbourne for Monday’s start of the Australian Open.