Holger Rune, No. 4 seed on Court 5, loses in first round of US Open to Roberto Carballes Baena

NEW YORK—Holger Rune didn't seem to care for the US Open's Court 5 before he played on Monday.

Safe to say that his opinion hasn't changed.

The No. 4 seed won't play on the fan-friendly side court, or on any other court at the USTA Billie Jean King National Tennis Center, this year following his 6-3, 4-6, 6-3, 6-2 loss to 63rd-ranked Roberto Carballes Baena.

It truly was a bizarre court assignment for a Top 4 player, but you need to play the cards, and court, you're dealt. With that in mind, perhaps it wasn't too much a surprise that Rune seemed rattled early and dropped the first set. Perhaps it also wasn't surprising that Rune swiftly turned things around to level the contest at one set all. Over the course of best-of-five-set play, the 20-year-old's already impressive record on tour and elite form would surely win out. (The two split their two meetings prior to today's rubber match.)

But when Rune broke Carballes Baena to get back on serve at 3-4 in the third—and then lost the next eight points—no one could have been sure of the Dane's destiny any longer.

Rune displayed irritation throughout this first-on first-rounder, but it was his play that ultimately let him down. A Rune double fault gave Carballes Baena three break chances as he returned at 4-2 in the fourth, and the Spaniard needed just one. After hitting a second serve, Rune's subsequent forehand promptly found the net. It was his 41st error of his forgettable day.

By match's end, Carballes Baena won 76% of first-serve points, compared to Rune's 61%, and he broke serve seven times. It also breaks open a relatively open section of the draw; the next highest seeds are No. 5 Casper Ruud, and a slew of talented Americans including Sebastian Korda, Frances Tiafoe and Tommy Paul.