With one pitch in the seventh inning Thursday, Gavin Floyd’s night went from dominant to devastating when the Braves pitcher left a 3-0 win against the Nationals with a fractured right elbow.

Floyd was tossing a two-hit shutout when he threw a curveball to Jayson Werth to start the seventh inning and began shaking his right arm. Television cameras showed a knot form immediately on his pitching elbow, not far from the scar from the Tommy John ligament-reconstruction surgery that Floyd had in May 2012.

After an X-ray was taken at the ballpark, a Nationals team doctor diagnosed the fracture of the olecranon, the curved bony end of the ulna, or what might commonly be referred to as the tip of the elbow. Floyd, 31, will fly to Atlanta to be examined by Braves doctors on Friday and have other scans performed.

Floyd was told that the fracture is unrelated to the Tommy John surgery to repair a torn ulnar collateral ligament. He also had a torn flexor tendon repaired at the same time as the “TJ” surgery.

Three Braves relievers worked an inning apiece to complete the three-hit shutout to open a four-game series and give the Braves their 23rd win in the past 30 games against the Nationals, including six of seven this season.

Braves head trainer Jeff Porter came onto the field and walked off with Floyd (2-2), who won his second consecutive decision in his ninth start, allowing two hits and one walk with six strikeouts in six innings. He signed as a free agent last winter and spent the first five weeks of the season on the disabled list completing his year-long surgery rehab.

Floyd lowered his ERA to 2.65 with his first scoreless outing of the season. He had allowed one earned run in half of his previous eight starts.