The 26-year-old featured in his first game of the season against the Blues west London rivals, replacing Petr Cech at half-time, and then having to step up to the plate in the penalty shoot-out, saving Moussa Dembele's spot kick.
But the modest stopper isn't prepared to take all the praise for his shoot-out heroics.
"The lads were fantastic; it wasn't just me making a save in a penalty shoot-out. The whole squad, the whole ethic of the team was brilliant," said Turnbull. "We were 10 men against a good Fulham team and we deserved to win.
"There was a fantastic spirit, a great bunch of lads and it was a difficult game playing with 10 men. It was a fantastic team effort.
"It's difficult to sit on the bench, you're not really expecting to come on but Petr got a knock to his head," he added.
"I came into the changing room and Petr said he was starting to lose a bit of his sight and it was just important to get myself out there and start warming up.
"I didn't know I was coming on until midway through half-time, so it was also important to get my mindset ready for the game."
Come the penalty shoot-out, Turnbull revealed that any preparation done before the game to drum up on the Fulham's penalty takers was blown out of the window when the Cottagers young guns were named in the starting XI, and the stopper admits it was a guessing game from 12 yards.
"It was difficult," he said.
"Normally we will look at players and look to see where they've placed penalties, but we didn't have anything for them.
"We only had an idea of Bobby Zamora's [penalties] and he went down the middle. I just had to get a feel for where the players were going and luckily enough for one of them I went the right way.
"It's pleasing but that's my job, that's what we train to do every week."