QPR booked their place in the second round after needing penalties to beat Swindon Town.
Summer signing Yeni Ngbakoto marked his debut with a goal but Jordan Stewart struck with 15 minutes remaining to send the game to the extra 30 minutes.
And, three minutes into the first period of extra time, Conor Washington scored his first goal for the club after good work by Sebastian Polter and Tjaronn Chery's selflessness.
However, James Brophy struck after Matt Ingram could only parry Jordan Stewart's shot into the Swindon man's path to take the tie to penalties. Matt Ingram saved from Anton Rodgers and Bradley Barry to take Rangers through
Below are five talking points to emerge from the tie.
Impressive debut
QPR signed Yeni Ngbakoto on the eve of their season opener against Leeds and he had an impressive debut against Swindon.
He looked lively on the right flank and marked his first appearance in blue and white hoops with a goal from two yards out.
It appears that he can fill the void that Matt Phillips leaves but his better position may be playing off Sebastian Polter as his pace can cause teams problems.
Multiple changes
Jimmy Floyd Hasselbaink can't be blamed for making eight changes – the fixture scheduling in August is ridiculous.
Rangers are playing Sunday-Wednesday-Sunday-Wednesday in the first two weeks of the season, just after coming off a hard pre-season campaign.
Injuries are more likely to happen if players play too many games so rotation is required as all west London clubs have done.
The fans aren't enthused either
QPR's record in cup competitions over recent years is shocking and the ambivalence Championship clubs show the EFL club is increasing every season.
With two home games in a week, Rangers fans are, naturally, going to pick the league game against Leeds United over a competition they are unlikely to win against a League One side.
For me, the EFL first round games should take place the weekend before the league season gets underway. It's already treated like a glorified pre-season friendly so why not give it Saturday billing so teams are more likely to play their first choice XIs.
Ingram strong
QPR have, in effect, two number one goalkeepers in Alex Smithies and Matt Ingram. The former Wycombe man was tested more than his colleague was on Sunday.
And he produced some fine saves to deny Luke Norris time and again while there was nothing he could do about Jordan Stewart's fine equaliser.
Jimmy Floyd Hasselbaink has a job on his hands as he could give either the job and they would perform.
That said, he will also have to keep one or the other happy if he is to persist with either stopper.
There was only one slip where he nearly allowed Norris in but Ingram recovered to gather.
Washington opens his account
It's been a long time coming but Conor Washington is on the scoresheet for QPR. He has deserved a goal for his work rate.
It was selfless play from Tjaronn Chery to tee up the Northern Irishman when he could have taken the shot himself following fine work from Sebastian Polter.
