British talent Kyle Edmund recorded the biggest win of his career as he beat experienced Frenchman Gilles Simon 6-4 3-6 6-1 at Queen's.
World number 18 Simon is the highest ranked opponent Edmund has ever beaten, trumping his previous best victory over world number 43 Martin Klizan at Dohar in January.
The 21-year-old, the world number 85, moves into the second round at the Aegon Championships, where he will now face either fellow Briton Dan Evans or another Frenchman, Paul-Henri Mathieu.
Edmund's excellent baseline game is more suited to clay and hard courts, but this performance on grass will serve as a confidence boost ahead of Wimbledon in two weeks' time.
The youngster was perhaps fortunate when a rain delay interrupted play just after Simon had taken the second set and appeared to be gathering momentum.
Edmund, however, recovered his poise during the break and came out firing, sealing two breaks en route to an impressive win.
"At the back end of the second set I had a bit of a mental lapse, I played a sloppy game to get broken" Edmund told the BBC on court afterwards.
"But coming out of the changing rooms I got my game back on the court and took my game to him."
Simon's scalp should not be under-estimated. He took Novak Djokovic to five sets at the Australian Open in January and put Andy Murray through an exhausting encounter on the same court at Queen's in the Davis Cup quarter-finals last year.
Murray has become something of a mentor to Edmund since their Davis Cup exploits together and the pair have also formed a habit of training together in pre-season.
"It's been great to be able to train with him," Edmund said.
"I've been very fortunate to do that. You speak to him, get tips, what he does on and off the court, seeing how professional he is.
"He deserves the success he gets, he puts in the work and it's good for me to see. It shows if I want to get the top of the game that's what I need to do."