Nigel Clough was delighted but relieved to see his side progress to the second round of the FA Cup, following a deserved 3-2 victory at Colchester United.
United were two goals to the good at the interval, but having being pegged back to 2-2, Chris Porter, on his return to the starting line-up, netted what proved to be the match winner from the penalty spot.
Speaking after the clash at the Weston Homes Community Stadium, Clough beamed:
"It was a very hard earned but deserved victory. To get two goals up, it should have been three, in the first-half was a great opening period for us.
"We didn't sit back after the break but probably through a bit of naivety we ended up conceding two goals.
"It was always the aim to go on and score more goals and thankfully in the end we got the winner."
The Gaffer continued: "There was a frustration that we hadn't put he tie to bed by half-time because we have told the lads since day one that you have to be ruthless when you are so much in control of a game.
"It wasn't for a lacking of trying or desire that we didn't build on our two-goal advantage and despite our frustration perhaps we should give Colchester some credit for their second-half performance.
"It was an FA Cup tie and at 2-0 they had nothing to lose. We still had the better chances in the second-half and that is why I was delighted with the end result."
Clough concluded by praising the character of his players, adding: "With 30 minutes left after they had just their second they were probably favourites but we dug in and ground it out and that pleases me.
"It was a good solid away performance, we showed character and there is more to come believe me."
The Blades are ball number 11 in Sunday's second round draw.