Blues boss Tuchel felt his Chelsea side made things 'harder than we needed to' during FA Cup triumph at Luton
The Blues had gone behind in the second minute to Town’s first attack, Reece Burke rising highest to glance Luke Berry’s corner into the net.
Although Saul levelled for the visitors midway through the half, they conceded again five minutes before the break, Harry Cornick racing on to Carlos Mendes Gomes' pass to beat Kepa Arrizabalaga.
With 25 minutes to go, Town looked like they were on the verge of one of the biggest upsets in their history, only for Timo Werner and Romelu Lukaku to find the net and end the Hatters’ dreams of a place in the quarter-final.
Speaking afterwards, Tuchel said: “We made things a bit harder than we needed it be.
“First set-piece we conceded a goal, then we were totally in charge of the game, had chances, not only to equalise, but to score a second and third goal.
“We didn’t do it, concede from the second shot, second goal. then it was difficult, but the difference between the (Carabao Cup) final and three days later here, I like how we played.
“We never lost our head, didn't get frustrated and kept on going and at the same time managed to find the decisive chances and deserved to win.”
Tuchel was also pleased to see both Lukaku and Werner net their first goals on domestic soil since the 5-1 victory over Chesterfield in the third round, as on the pair, who cost around £150m, he continued: “Timo played well, I’m happy for that and Romelu got his goal, that’s why we had them on the pitch and left them on the pitch.
“These matches in the moment are the most important thing for them.
"Even if they think ‘I should have played this match or this match,’ but we want them to play with full focus and to take this seriously, as this is where you grow in confidence and where you can get your confidence back.
“Timo did very well and Romelu got his goal, so it was only positive.
"On the other hand, this is why they are here, in cup matches like this, where it’s hard to show permanently that you're the better team.
“Your qualities you need to show in the better moments, to go through and that you’re able to forget the game as you’re in the draw for the next round.
"This is what we did and that’s why I’m happy.”
Speaking about the win, Werner himself added: “Cup games are always very difficult games, especially when you play away against a second division team who did very well, who gave everything.
"At the end I thought we were the better team and we won.
"It was hard work, but we are happy that we won.”