St Johnstone's back line continued to get the plaudits following their 1-0 Scottish Cup win at Dundee.
Guy Melamed's well-taken goal in the 20th minute ultimately sent the Betfred Cup winners through but goalkeeper Zander Clark and their defence played a major role.
Clark saved a 75th-minute penalty from Charlie Adam, although he got away with dropping a cross when Danny Mullen was flagged offside from the initial cross after knocking the ball home.
Dundee struggled to create clear-cut chances although Paul McMullan hit the bar from one of several decent long-range efforts.
Saints have now kept clean sheets in five of their past six games and the Perth side have only lost to Celtic and Rangers, narrowly to both, in 2021.
Wing-back Callum Booth told Saints TV: "There were a couple of nervy moments with them shooting down the hill with backs to the walls at times. But overall we rode it out well.
"Zee has made a great save for the penalty. We didn't really feel too threatened although they were piling bodies forward towards the end, as you are going to do in a cup tie. They ended up with three or four strikers on the pitch.
"The boys defended really well, as they have done all season. We are on a good run of clean sheets so long my that continue."
The impressive defensive displays have been built on Clark behind the back three, with Liam Gordon commanding in the centre and Jason Kerr and Jamie McCart thriving either side of him.
Wing-backs Booth and Shaun Rooney again played their part at Dens Park but the left-sided player was quick to credit the players behind him.
"The three centre-backs have been absolutely brilliant, and Zander as well," he said.
"They are big boys and the system we play suits them. The two of them driving out with the ball as well, you see Jase putting in crosses in the second half, which he is probably not used to doing until the start of this season.
"The run of clean sheets shows how important they have been, and Zander as well. They have been absolutely brilliant all season.
"The four of them together have been the real solid base for us to start picking up points and we have won a lot of games 1-0."
