In the first game on the road in 2020/21, following on from the opening day win against Brentford, they showed what they are now all about.
Unlike last season, when Swansea had their way with Blues too easily, they found Aitor Karanka's side well organised, durable and carrying a threat, too.
Blues might easily have taken all the points as there were certainly moments of concern for the side defeated by the Bees in Play-Off Sermi-Finals.
But overall the stalemate result was probably about fair as Blues tactically got things right and once again played with gusto and backbone.
Blues, making just the one change to last week's starting eleven - Neil Etheridge in for his debut - got to grips with their opponents and the tempo of the game well.
With a quarter gone their pressing and understanding of shape and what was required was clear.
And they had a half-chance, from a free-kick routine that was delivered in by Ivan Sanchez, and flicked wide, off balance, by Kristian Pedersen.
And in the 27th minute, with Swansea by now frustrated, Blues had the first real attempt on goal, through Jon Toral.
Lukas Jutkiewicz won the first ball forward in the air and had an attempt blocked before it popped back out to Toral, who fired it towards the bottom corner, on the full.
Coming through a crowd of bodies and bouncing just in front of him, Freddie Woodman made an excellent save, pushing the ball behind.
Swansea regrouped and responded with a strong header by Ben Cabango at a well delivered corner, but George Friend was in close attendance to ensure the attempt flew over.
In the 39th minute Matt Grimes tried to catch out Etheridge at the free-kick, to the left edge of the area. Grimes bent the ball low round the outside of the wall, hoping Etheridge would edge out and across in expectation of the cross - but he dived low to get his body right behind the ball.
Blues continued to cause problems going the other way however, with Jeremie Bela's strong running a problem, as was Ivan Sanchez's clever, neat football.
From one raid Adam Clayton bashed the ball first time at goal from the edge of the box and it was only the big figure of Marc Guehi, who ducked his head into the flight path, that stopped it going past Woodman.
In the 45th minute again Blues put the pressure on and from a low Toral cross towards the near post Joe Rodon made a fantastic clearance, away from Jutkiewicz, who was about to apply the finishing touch.
There was a big flashpoint after the half-time whistle went and the players made their way to the tunnel. Toral was involved in an exchange of words with Swansea coach Alan Tate and was promptly grabbed round the throat the shoved to the ground. It sparked a bout of jostling and shoving as the benches and players came together, causing a bottleneck at the entrance to the dressing rooms.
Referee Gavin Ward took a step back and waited for the melee to subside; and Tate assumed his usual position in the technical area for the second-half, signifying that no action had been sanctioned against him during the interval.
Half-time: Swansea 0 Blues 0
Swansea made a sprightly start to the second period. A clever ball was played in behind Harlee Dean - the first time Blues had got exposed like that - and Morgan Gibbs-White went on, steadied himself but struck a low shot that Etheridge was equal to.
A nice, intricate passage of play wide on the left involving Pedersen, Clayton and Toral enabled Bela to cut onto his right foot and fire at goal, but it took one bounce in front of Woodman and proved easy to save.
Toral's afternoon came to an end in the 63rd minute, with Gary Gardner entering the fray. Blues appeared to therefore go 4-1-4-1 with Clayton in front of the back four.
Swansea had got into far more threatening positions in the second period as opposed to the opening half and Karanka felt the need for alteration.
But that's not to say Blues weren't still a threat themselves.
After some probing inter-play on the left, a corner was forced and from Sanchez's flag kick Dean got up and powered a header goalwards that Woodman grabbed at the second attempt (74 minutes).
Moments later, in a rare occurrence, Pedersen got dragged across in the area and Blues lost their shape. The ball was switched to the spare man, Connor Roberts. Instead of letting rip from a good angle he tried to slide the ball across for Gibbs-White but Blues harried the danger away.
Blues weren't done, though, and after a forceful attack down the right, a Sanchez cross was set back by Gardner for Bela whose 22-yarder looped off Korey Smith and just wide. From three successive corners Rodon made three superb headers to deny Blues, who swarmed around glorious deliveries in by Sanchez.
With four minutes left Blues worked the ball from their own half well, side to side and then forward, to fashion a crossing angle for Maxime Colin.
He deftly lofted the ball towards the penalty spot where Bela had sneaked in and his dividing header rebounded off Roberts, stopping the threat at Woodman.
Then with two minutes to go Etheridge made a fantastic stop to thwart Swansea, who lobbed the ball into the thick of it with a long throw.
The ball dropped invitingly to Guehi and he smashed it hard at goal from just inside the box but Etheridge's reflexes were sharp and he dived to the left to beat it away.
Swansea City (3-5-2): Freddie Woodman; Ben Cabango, Joe Rodon, Marc Guehi; Connor Roberts, Korey Smith, Matt Grimes (captain), Jake Bidwell; Morgan Gibbs-White; Jamal Lowe (Liam Cullen 85), Andre Ayew.
Substitutes not used: Steven Benda, Kyle Naughton, Jay Fulton, Wayne Routledge, Yan Dhanda, Kristoffer Peterson.
Blues (4-2-3-1): Neil Etheridge, Kristian Pedersen, Ivan Sunjic, Lukas Jutkiewicz, Harlee Dean (captain), Ivan Sanchez, Jeremie Bela, Maxime Colin, George Friend, Jon Toral (Gary Gardner 63), Adam Clayton.
Substitutes not used: Zach Jeacock, Marc Roberts, Dan Crowley, Scott Hogan, Steve Seddon, Agustin Medina.
Booking: Dean (11)
Referee: Gavin Ward