It was a long way from Colorado to Buenos Aires for Neil Magny.

But the trip couldn’t have seemed anywhere near as long as the 17-plus minutes he spent in the cage with Santiago Ponzinibbio on Saturday night in the main event of UFC Argentina.

The surging Ponzinibbio showed why he’s one of the sport’s most underrated fighters as he picked apart Magny before finishing things with a faceplant knockout at 2:36 of the fourth round.

That’s seven straight victories for Ponzinibbio — which is the second-longest active win streak in the UFC welterweight division behind Kamaru Usman’s eight — and nine in his past 10.

“I have 15 fights in the company and 13 victories,” Ponzinibbio said. “I am ready for the best.”

Things started going south fast for Magny, as he took a perfectly executed left jab to his right eye early in the first round, which had him immediately covering the eye with his hand. Magny managed to clear the cobwebs, but Ponzinibbio, an American Top Team competitor who returned to his homeland of Argentina to take the headline bout, kept swarming Magny with his pressure and never feeling comfortable.

Ponzinibbio’s most anxious moment of the fight came in the second as the result of an accidental headbutt which opened a nasty gash on his eyelid, one which caused a timeout so the doctor could check the cut. But after a tense moment or two, Ponzinibbio was cleared to continue.

And from there, the bout simply became more one-sided. Ponzinibbio’s leg kicks dropped Magny over and over throughout the later rounds. Magny would try to goad his foe to the ground, but Ponzinibbio never took the bait.

The fourth round got straight up uncomfortable to watch, as Magny continued to get dropped with low kicks. Magny was tough, his corner wasn’t doing him any favors, and nor did referee Herb Dean wave things off, so the final result, a face plant KO caused by a wicked right cross, seemed inevitable.

“I use my pressure, I have a great opportunity, he’s difficult to finish but keep patient and I get the finish,” Ponzinibbio said.

Ponzinibbio improved to 27-3 with his 15th career KO and 21st stoppage win. Magny (21-8) has a two-fight win streak snapped. Seven of his eight career losses are by stoppage.

Full UFC Fight Night 140 Results:

Neil Magny vs. Santiago Ponzinibbio — Ponzinibbio def. Magny by KO (punch) at 2:36 of Round Four
Darren Elkins vs. Ricardo Lamas — Lamas def. Elkins by TKO (elbows and punches) at 4:09 of Round Three
Khalil Rountree vs. Johnny Walker — Walker def. Rountree by KO (elbows and punches) at 1:57 of Round One
Cezar Ferreira vs. Ian Heinisch — Heinisch def. Ferreira by unanimous decision (30-27, 29-28 x2)
Guido Cannetti vs. Marlon Vera — Vera def. Cannetti by submission (rear naked choke) at 1:31 of Round Two
Poliana Botelho vs. Cynthia Calvillo — Calvillo def. Botelho by submission (rear naked choke) at 4:48 of Round One
Bartosz Fabinski vs. Michel Prazeres — Prazeres def. Fabinski by submission (guillotine choke) at 1:02 of Round One
Alexandre Pantoja vs. Ulka Sasaki — Pantoja def. Sasaki by submission (rear naked choke) at 2:18 of Round One
Austin Arnett vs. Humberto Bandenay — Arnett def. Bandenay by unanimous decision (29-28, 29-27 x2)
Hector Aldana vs. Laureano Staropoli — Staropoli def. Aldana by unanimous decision (30-27 x3)
Devin Powell vs. Jesus Pinedo — Pinedo def. Powell by unanimous decision (30-27 x3)
Anderson dos Santos vs. Nad Narimani — Narimani def. dos Santos by unanimous decision (30-27 x3)