Nigel Clough praised the Blades professionalism after Sunday's 2-0 victory at Cambridge United in the FA Cup.
The second round win set up an away tie against Aston Villa in round three and Clough described the success at The R Costings Abbey Stadium as a job well done.
Speaking after goals witnessing from Jose Baxter and substitute Jamie Murphy, the Gaffer remarked:
"It was comfortable in the end but we had to work very hard to win the game, as we knew we would against a very good Cambridge side.
"The first goal was crucial and Jose (Baxter) showed a real touch of quality in the box.
"What disappointed me, the only thing in the whole game, was the way we allowed Cambridge opportunities for 20 minutes or so afterwards.
"But after that spell we controlled long periods of the game, rarely looked troubled and produced a disciplined and professional second-half performance.
"We deserved our spot in the third round and now we can look forward to a fascinating tie at Villa Park."