Nothing was coming easily to John Isner over the first three months of this year, and he was essentially a non-factor in every tournament he entered.

Until now.

The big-serving American is in the semi-finals of the Miami Open for the second time in the past four years, after overpowering South Korea’s Hyeon Chung 6-1 6-4 in just over an hour.

The 14th-seeded Isner finished with 13 aces, won all but one of his 32 first-serve points and avenged a loss to the 19th-seeded Chung at Auckland in his first match of the year in January.

“I played extremely well,” said Isner, who dropped six of his first eight matches of 2018 before arriving in Miami and winning eight of his nine sets played at Key Biscayne so far.

“Every match I’ve played in this tournament, I’ve gotten better. I’ve gotten stronger and that’s a very, very good sign.”

He’ll hope that trend continues in the semifinals.

Isner – who ousted second-seeded Marin Cilic earlier this week – will next face either No. 5 seed Juan Martin del Potro of Argentina or No. 20 Milos Raonic of Canada.

Del Potro and Raonic play late Wednesday night in another quarter-final.