Manchester United's Marouane Fellaini celebrates scoring their second goal . (Reuters Images)
Manchester United turned frustration into jubilation as they planted one foot in the League Cup final after a late Marouane Fellaini header gave them a 2-0 win over Hull City in the first leg of their last four clash on Tuesday.
Juan Mata had given United the lead early in the second half, but their failure to kill off the tie when comfortably on top had left the home fans fearing a testing return encounter as the seconds ticked away at Old Trafford.
The victory kept the Portuguese coach on course for a first trophy at the club and continued United's superb recent form with a ninth successive victory in all competitions, but the demanding Mourinho was far from satisfied with what he saw.
"I was a bit disappointed yes," he told Sky Sports.
In only his second game as Hull boss, fellow Portuguese Marco Silva had to deal with an injury crisis that left him with only 14 fit senior players and there was a makeshift look about them as United took control early on.
Mata drew an excellent save from Hull keeper Eldin Jakupovic after two minutes, while Henrikh Mkhitaryan sidefooted wide after being set up perfectly by the Spaniard.
The visitors, whose injury woes got worse when Markus Henriksen went off after 19 minutes with a shoulder problem, did have arguably the best chance of the first half, however, when Adama Diomande headed against the base of the post.
United almost doubled their lead as Paul Pogba rattled the post with a free kick, but the frustration levels were rising until Belgian Fellaini came off the bench to make his mark and provide a cushion for the second leg on Jan. 26.
Southampton and Liverpool contest the other semi-final, with the first leg at St Mary's on Wednesday.