Two goals from striker Michy Batshuayi spared Chelsea blushes as the Blues endured a nervy night against Bristol Rovers but go through to the 3rd round of the EFL Cup with a 3-2 victory over the League One side at Stamford Bridge.
The Belgium striker's goals, the first and third should have meant the Premier League side had a comfortable passage into the next round, but, after Victor Moses had put the Blues into a 2-0 lead, frailties in the centre-back position opened up and Peter Hartley brought the visitors back into the game, with a clever header.
Then, seconds into the restart of the second, half, Chelsea conceded a penalty which Ellis Harrison comfortably slotted home.
It was the absence of any centre-backs again that led to the chance and eventually head coach Antonio Conte rectified the situation, bringing on John Terry and Eden Hazard and Oscar.
That calmed the nerves of the majority of the 39,266 crowd.
Chelsea started off with real intent, with a number of players fighting for their first-team duty.
Cesc Fabregas started his first competitive game of the season, while the likes of Rubén Loftus-Cheek, Victor Moses and Ola Aina attempted to prove to head coach Antonio Conte they deserve to be in the squad. failing that and with the transfer window closing at the end o the month, the last three of those four will most probably be farmed out on loan.
The away side, understandably are put under sustained pressure from the off, hoping for a counter-attack.
Michy Batshuayi attempted an audacious lob of Rovers' Steve Mildenhall on eight minutes, but the former Southend and Millwall stopper showed all his experience to clear the ball away for a corner.
Mildenhall, in fact was on work experience at our sister paper the South London press for a spell, while he was a stopper at Millwall. He was understandably on the sports department.
Some wonderful wide play by Pedro and Nemanja Matic almost reaped dividends on 15 minutes, but the former Barcelona man, inched his curling right-footer just over Mildenhall's crossbar.
Batshuayi should have scored on 19 minutes but screwed his effort wide of target.
Loftus-Cheek showed a wonderful turn of pace two minutes later, before unleashing a vicious daisy-cutter that beat Mildenhall but unfortunately rebounded off the keeper's right post.
Pedro was next up to pepper the Rovers goal, but the keeper held firm.
The incessant pressure finally paid off on 28 minutes when excellent recovery work by Pedro saw the ball played to Loftus-cheek on the edge of the area, it was then passed on to Matic who crossed for Batshuayi who rammed home a smart left footer.
Two minutes later and it was 2-0. This time Moses was on the spot to tap home from close range with the Rovers defence in disarray.
But with just their first serious attempt on the Chelsea goal, Rovers got one back on 35 minutes. A curling right-wing free kick by Chris Lines was met full on the head by virtually unchallenged Peter Hartley, who beat the outstretched right arm of Begovic.
Incredibly useful Rovers could have levelled two minutes later when another curling high ball from the right connected with Ellis Harrison's head but the ball, inched wide of Begovic's far post.
But the home side restored their 2-0 goal buffer five minutes before the break when excellent byline play by Loftus-Cheek saw the youngster cut the ball back to in-running Batshuayi who smashed the ball past exposed Mildenhall from six yards out.
Fabregas almost made it four but his low, left footer was well held by the Rovers' goalkeeper.
Conte restarted the match with the same side.
Chelsea's centre-backs went AWOL two minutes after the restart allowing substitute Marty Taylor to race through. Pedro did the professional thing and fouled the speed merchant inside the penalty area.He was only given a yellow card for his misdemeanour, but up stepped Ellis Harrison to send Begovic the wrong way and make the score 3-2.
The away side piled on the pressure and Harrison almost equalised with a blistering opportunistic volley on 65 minutes, but the fantastic effort, created once again by a ponderous centre back play, clipped off Begovic's crossbar.
Begovic was forced into a fine save to thwart Harrison again, this time the Bosnia goalkeeper got a fingertip to the zipper of a shot and sent the ball over the crossbar for a corner.
A piece careless play by Matic allowed Stuart Sinclair to latch onto the ball. But his effort just went wide of goal on 66 minutes.
Conte decided to make a change on minutes on 74 minutes, replacing Pedro with Eden Hazard.
He was quickly followed by the arrival of John terry who replaced injured Ola Aina.
Oscar was the final Chelsea sub, taking the place of Loftus-Cheek on 82 minutes.
The Blues saw out the final minutes and will now be in the draw of the third round tomorrow.
Teams: Chelsea: Begovic, Aina, Cahill, Ivanovic (c), Azpilicueta, Pedro, Fabregas, Matic, Moses, Loftus-Cheek, Batshuayi.
Subs, Courtois, Terry, Chalobah, Oscar, Hazard, Solanke, Diego Costa
Bristol Rovers: Mildenhall, Leadbitter, Brown, Hartley, Clarke, Harrison, Limes, Bodin, Sinclair, James
Subs, Puddy, Taylor, Clarke, Easter, Montano, Broom, Gaffney
Referee: Keith Stroud