Ian Flanagan and Jonathan Marray both had their fairytale runs ended by seeded players at Queen's.
Flanagan, who had earlier beaten Mark Philippoussis, was thrashed by fifth seed Sebastien Grosjean 6-2 6-0.
But Marray pushed sixth seed Lleyton Hewitt to the limit before succumbing 7-6 (7/2) 7-6 (10/8).
Marray forced six set-points in the 12th game of the first set, and saved four match-points along the way, but Hewitt proved just too strong.
"I'm a bit disappointed I didn't take it to three [sets]," Marray told the BBC, "but I had a great time and it was a great atmosphere.
"I felt a little nervous before but once I got out there I really enjoyed it.
"I stuck to my gameplan and I think I caused him a few problems so I'm pretty happy."
Hewitt was fulsome in his praise for the young Briton.
"He played extremely well - he served extremely well for the whole match," said Hewitt.
"In the end I just played the bigger points better in the tie-break.
"He obviously enjoys coming to the net and he played a lot of good low volleys."
Flanagan, ranked 886th in the world, was unable to produce the kind of display that had seen him beat Philippoussis and Victor Hanescu.
Grosjean was simply too consistent from the baseline, breaking five times to seal a comfortable win in just 50 minutes.
Playing his first match on the Centre Court at Queen's, Flanagan admitted he had been some way short of his best form.
"The atmosphere was great and the fans have been superb, it's just a shame I couldn't give them something to cheer," he said.
"Grosjean is just the type of person you don't want to play when you're a little bit nervous.
"The one thing you don't want is someone making every single ball and putting you under pressure and unfortunately I didn't play anywhere near my best tennis.
"But it's been a great week and hopefully I'll be back here next year."
Flanagan said he was still hopeful of receiving a wildcard for Wimbledon.
"I think I deserve a wildcard but it's out of my hands," he said.
He falls outside the LTA's selection criteria for wildcards, but the All England Club has three more to be handed out at its discretion.