John Isner reached his first final of the 2018 season at the Miami Open on Friday, with the 14th seed putting in arguably his most impressive performance of the year to snap Juan Martin del Potro’s winning run in some style.

Isner, who has largely struggled so far this season, broke twice in the opening set as he quickly went a set up in the last four clash, and remained solid on his own serve in the second set as del Potro began to pose more of a threat. The American dominated a second set tiebreak, eventually prevailing 6-1, 7-6(2) in just an hour and 23 minutes to reach the fourth Masters 1000 final of his career, and his first since the Paris Masters in November 2016.

Isner in action during the match (Getty Images Sport/Clive Brunskill)
Isner in action during the match (Getty Images Sport/Clive Brunskill)

Isner takes apart weary del Potro to reach first Miami Open final

The Miami Open hasn’t been a massively successful tournament for Isner in the past, with his semifinal showing in 2015 being the only time he’s been further than the fourth round, and he was certainly the underdog against del Potro, who came into the tournament fresh of titles in Acapulco and Indian Wells. However, perhaps weary from a tough quarterfinal clash, del Potro could do little to match the 14th seed today.

Serving first, Isner got off to a flying start as he broke del Potro early on and eventually built up a quick 3-0 lead. The Argentine, seeded fifth, was able to get on the board to provide some response, though wasn’t quite firing at full gear in the opening set, and was eventually made to pay for it; having held serve comfortably once again for a 4-1 lead, Isner broke for a second time in the set, and safely served out the opening set to put himself just one set away from his 25th ATP World Tour final.

Del Potro and Isner greet each other following their semifinal encounter (Getty Images Sport/Clive Brunskill)
Del Potro and Isner greet each other following their semifinal encounter (Getty Images Sport/Clive Brunskill)

After a drab first set by his standards, del Potro was able to start the second set well with an opening hold, and eventually eased into the match with some solid form; he could do little to try and break down Isner however, who remained solid on serve throughout the set. The American missed a break point at 4-4 which would have allowed him to serve out the match, and though he had no further opportunities to break, he himself was hardly threatened on serve in his remaining service games. In the ensuing tiebreak he got off to a quick 3-0 lead, and after the Argentine won two points on serve, Isner never looked back, storming away with the final four points to seal the victory.

Before Miami, Isner was well outside the top 100 in the race to London following a poor start to the season, though the world number eighteen will have greatly improved his position in that ranking, as well as being incredibly confident after his second top-ten win of the tournament. He will face either 16th seed Pablo Carreno Busta or fourth seed Alexander Zverev in the final on Sunday.