Pablo Carreno-Busta broke new ground at the US Open, seeing off Diego Schwartzman in straight sets to reach his maiden grand slam singles semi-final.

Having also reached the quarter-finals of the French Open earlier this year and the doubles final here 12 months ago, the Spaniard displayed greater top-level composure this time to register a 6-4 6-4 6-2 success.

Carreno-Busta, seeded 12th, is yet to drop a set at Flushing Meadows and looks a strong contender to make the final in a wide-open bottom half of the draw.

He will meet Sam Querrey or Kevin Anderson in the next round.

Schwartzman was left to rue the effect of incessant errors, mixing some stunning winners with sloppy mistakes which made things easy for his opponent at times.

It was a theme from the very start as three off-target backhands helped Carreno-Busta break to love in the opening game and Schwartzman's erratic nature was not helped when he was enraged by HawkEye calling a ball in.

A long Schwartzman forehand gave Carreno-Busta the chance to serve out the first set at 5-2, but he suddenly showed signs of nerves, putting too much on a second serve and double-faulting when facing break point.

Carreno-Busta's serve was back to its booming best next time out, though, to seal the set and the Spaniard had another early in-road in the second set, taking a 2-1 lead after Schwartzman again put too much heat on and netted.

The Spaniard, though, then seemed shaky, dolloping a drop shot into the net as the 29th seed broke right back.

Schwartzman had the crowd at his back as stiff defence secured a hold, and he seemed to be growing into the contest until the ninth game when two double faults had Carreno-Busta on track for a two-set lead, secured when a pair of aces at 15-30 down were backed up by more scorching serving.

Schwartzman was reportedly struggling with a groin injury pre-match and he offered little resistance in the third set, save for a stunning reflex, volleyed lob winner at the net - the shot of the match - but even that game went to Carreno-Busta and Schwartzman smashed a forehand high into the Arthur Ashe Stadium crowd to see the Spaniard convert his first match point.

STATISTICAL BREAKDOWNCarreno-Busta [12] bt Schwartzman [29] 6-4 6-4 6-2

WINNERS/UNFORCED ERRORSCarreno-Busta - 30/30Schwartzman - 21/35

ACES/DOUBLE FAULTSCarreno-Busta - 7/3Schwartzman - 4/3

BREAK POINTS WONCarreno-Busta - 6/8Schwartzman - 2/10

FIRST SERVE PERCENTAGECarreno-Busta - 64Schwartzman - 63

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVECarreno-Busta - 65/63Schwartzman - 62/33

TOTAL POINTSCarreno-Busta - 97Schwartzman - 72