Manchester United laboured past Sheffield United to make way into the fourth round of the FA Cup.
United overcame Sheffield with a penalty from Wayne Rooney with time virtually up, but its performance against third-tier opposition was another display lacking attacking intent.
When substitute Memphis Depay tried his luck with a low shot which went comfortably wide in the 66th minute, it was United's first attempt at goal, and was greeted with sarcastic cheers by supporters.
Depay was felled in the box in the third minute of injury time by Dean Hammond, and Rooney scored from the spot.
United manager louis van Gaal regarded the result as more important than the performance. "You have to play more quickly than we did in the first half," Van Gaal said. "They are defending with 10, 11 players behind the ball. It's more easy to defend than attack."
Premier league struggler Swansea was humbled in a 3-2 loss at fourth-tier Oxford on Sunday for the first big shock in the third round of the FA Cup.
Fifty-four places separate the teams in the English football pyramid and Ecuador winger Jefferson Montero gave an indication of the supposed difference in class by backheeling Swansea into the lead in the 23rd minute.
However, Oxford scored three goals in 14 minutes either side of the halftime break and Bafetimbi Gomis' 66th-minute reply proved only a consolation for Swansea.
Swansea, which is in the midst of a relegation fight in the Premier league, came unstuck after making 10 changes for the game.
Chelsea endured third-round humiliation at the hands of lower-league opposition in Bradford last season but had no problems 12 months on, beating Scunthorpe 2-0 through goals by Diego Costa and Ruben loftus-Cheek.
Chelsea remained unbeaten under Guus Hiddink, who took over until the end of the season after Jose Mourinho's firing last month, but it wasn't a convincing performance by the seven-time FA Cup winners.
Under pressure from two defenders, Costa turned in Branislav Ivanovic's right-wing cross for the 13th-minute opener. loftus-Cheek, a halftime substitute, ended Scunthorpe's resistance in the 68th.
Hiddink guided Chelsea to the FA Cup title in 2009, also as an interim manager.