Having lost the first set against World No. 70 Ramos-Vinolas, Federer steadied the ship with a strong second set and looked poised to sustain his momentum in the decider. Indeed, just 12 months ago in Shanghai he had found himself in worse trouble when he faced six match points against Leonardo Mayer in his opening match. On that occasion, Federer had narrowly escaped and gone on to win the title.
But there was to be no let-off against the resilient Ramos-Vinolas, who did not let the opportunity to claim his first Top 10 win slip through his grasp. The 27 year old stayed strong on serve in the third set and snuck a crucial break in the eighth game.
“I definitely thought of last year's match,” said Federer. “But at the same time it was a completely different match. Playing a lefty maybe also had something to do with it. Who knows? Albert was doing a good job of trying to stay on the offensive as well as I was trying to do the same. There were some good rallies there.
“I had my chances. I just couldn't make it today. I’ve got to look into it. But at the end of the day this can happen during the year. Unfortunately, here in Shanghai where I was defending champion, I was really hoping again to play a great tournament.
“I just think the first round here in Shanghai has always been historically quite difficult, getting used to the conditions and the surface and the balls. The balls play very different than in other places. Last year I got lucky. This year I didn't. So it's a pity.”
Ramos-Vinolas is the lowest-ranked player to beat Federer since July 2013, when World No. 114 Federico Delbonis stunned Federer in the Hamburg semi-finals.
“I'm always cautious,” said Federer, who had lost just three games in his one previous meeting with Ramos-Vinolas at Wimbledon three years ago. “I don't underestimate or lack respect for anybody out there. These guys are all touring professionals, they know what they're doing. The margins are so small.
“I played him at Wimbledon before, so I knew him. I've seen him play. He's definitely improved since then. That was a while back and that was not his favourite surface. I was aware that he could give me a tough workout and even beat me.”
Defeat for Federer in Shanghai, where he was defending 1000 Emirates ATP Ranking points, also puts in jeopardy his chance of finishing as year-end World No. 2 behind Novak Djokovic.
The Swiss started the week 770 points behind Andy Murray in the year-to-date standings. Murray has the chance to stretch that lead even further this week now, only defending 90 points from his third-round exit against David Ferrer last year. The Scot begins his campaign on Wednesday against Steve Johnson.