Fulham survived a scare at Leyton Orient as they went from 3-0 up and coasting to hanging on progress after a 3-2 win.
Dennis Adeniran scored on his debut on 29 minutes, heading home Sean Kavanagh's corner, and was booked for celebrating with the fans.
Two goals in three minutes appeared to suggest the Whites were cruising into the second round as Cauley Woodrow blasted home a 30-yard free kick before robbing Aron Pollock to score.
However, Paul McCallum scored twice in quick succession to set up a nervy final nine minutes.
Slavisa Jokanovic made 11 changes from the side that beat Newcastle on the opening weekend of the Championship season and included four players from the academy; highly rated Ryan Sessegnon, the first player born after January 1 2000 to play for the club, Adeniran, Lucas De La Torre and Adetayo Edun making their debuts.
Orient had made five changes themselves and were on the back foot for most of the first half.
And Fulham led on 29 minutes when Kavanagh's corner was met by Adeniran to give the Whites the lead.
The 17-year-old ran towards the Fulham supporters in celebration and was booked by referee Andy Davies for his troubles.
It was then Woodrow's time to shine in the second half as he scored an early contender for goal of the season by slamming the ball, rolled to him from a Scott Parker free kick, into the net from 30 yards.
He scored again three minutes later as he intercepted Pollock and curled the ball past Orient keeper Sam Sargeant.
However, Fulham's weakness at set pieces and balls into the box was exposed once again as McCallum, who had both come on as substitute, headed home Dean Cox's corner to pull one back.
The same two linked up again six minutes later to setup a grandstand finish but the Whites held on.
