Just less than three weeks removed from his father's unexpected death at the age of 58, Johnson defeated Croatian Borna Coric in four sets and broke down in tears immediately afterward.
Johnson's father served as his youth tennis coach, and continued to coach for more than 35 years prior to his death.
The younger Johnson, who won two NCAA Men's Singles titles and four straight NCAA Team titles at USC, has faced two tough battles on the court at Roland Garros on top of his emotional battle.
In the first round, 25th-seeded Johnson won the first two sets, but dropped two tiebreakers and needed a fifth set to top Yuichi Sugita (JPN).
Johnson also won the first two sets in his match against Coric today before dropping the third and fighting off two set points in the fourth-set tiebreak to clinch a victory.
Immediately after his match-ending forehand winner, he dropped to the clay.
"I just knew he was looking down on me on that last point and gave me the strength to finish it off," Johnson said of his father after the match. "Physically, I'm okay. Emotionally, I'm a mess. He always wanted me to be a fighter and a competitor so that's what I'm going to do, day in and day out. That's the only thing I can do."
Johnson's perseverance has earned him a spot in the third round, where he'll face No. 6 seed Dominic Thiem (AUT) on Friday at 2 a.m. PT.
What a moment.
-- Tennis Channel (@TennisChannel) May 31, 2017
????@SJohnson_89 with @Jon_Wertheim after his victory v. Borna Coric at @RolandGarros just weeks after losing his father. #RG17 pic.twitter.com/MYm7FMIQs8
