London - Ernests Gulbis says his Wimbledon upset of Juan Martin Del Potro was a fitting reward for his refusal to throw in the towel when the colourful Latvian's career hit rock bottom.
Gulbis sprang a second round surprise on Thursday as the world number 589 defeated former US Open champion Juan Martin Del Potro 6-4, 6-4, 7-6 (7/3).
Gulbis will face three-time champion Novak Djokovic in the third round after scoring his best result in three years.
The 28-year-old Latvian was ranked in the top 10 in 2014 -- the year he beat Roger Federer en route to the French Open semi-finals.
Since then, Gulbis has slumped badly and his Wimbledon opening round win over Victor Estrella, was his first on tour in 13 months, a decline which has seen his ranking crash to his lowest position in 12 years.
Gulbis, the son of a billionaire, has often been accused of squandering his vast natural talent.
Asked if he had ever thought he was running out of time to make his mark, Gulbis said: "Maybe now is the last chance train. Maybe there is going to be another last chance in five years. Who knows.
"The previous years maybe I had a worse approach. Even the year when I played really well, 2014, after Paris, I did a mistake that I played next week in Queen's.
"I should take the week off. I should prepare better. But I rushed on grass. Then you lose little bit confidence on grass, you lose one match, it's that kind of thing.
"But you learn on your mistakes. I've been around for a long time. I made a lot of good decisions, and also a lot of bad decisions. So try to learn from the bad ones."
Gulbis wouldn't be drawn on whether he had contemplated hanging up his racquet for good, insisting it was mainly injuries that had hampered him of late.
"It's a long story. There is no miracle. It's a private story. I think it's tough to give you definition in couple sentences, or even in a half-an-hour speech," he said.
"I had two muscle tears, one in the calf, one in abdominal. Actually, I came to Roland Garros same like I did here: without playing any points.
"If you're not top shape, you don't have a chance. Then I went to Prostejov, to a Challenger. I tore my abdominal muscle in the first round.
"This has been the story this season, you know."
Gulbis's sudden renaissance could come to an abrupt halt in the next round against his old friend Djokovic, who trained with the Latvian when they were teenagers working with renowned coach Nikola Pilic.
"Novak was coming and going. We practised a little bit. We had a really nice relationship, a really good relationship," Gulbis said of the Serb who he trails 6-1 in career meetings.
"I had nothing to lose also this match, and I played well. I'm going to have even less to lose next match. Maybe I'll play even better!"
Del Potro, a Wimbledon semi-finalist in 2013, was pushed to the brink of retirement after three wrist surgeries.
So the Argentine 29th seed has an extra appreciation for Gulbis's achievement, even if he would have preferred not to be on the receiving end of the upset.
"I know how good is Ernests on grass and if he has a good day, he can beat all the guys, because he already made it in the past," Del Potro said.