The Tigers boss conceded the after-effects of Tuesday's home loss to third-placed Watford, in which the hosts missed the opportunity to open up a seven-point gap, plagued his side throughout the first half of the 1-0 win against an out-of-form Middlesbrough.
There was little to separate the two teams until the 62nd minute when Republic of Ireland international Robbie Brady curled a free-kick low around the wall to catch out goalkeeper Jason Steele, who could only push it into the roof of the net.
It means automatic promotion remains in Hull's hands and they face the struggling trio of Wolves, Bristol City and Barnsley in their final five games.
Bruce said: "Tuesday was a huge disappointment to us all and I'm going to admit (on) Thursday and Friday they were still disappointed. It really took us to half-time to get going again, but we showed something, a bit of resilience and that determination to get a result. We don't want to be sitting through too many of them."
On match-winner Brady's fortunate strike, Bruce joked: "I've heard some nonsense that he watched somebody do it, whether it was (Cristiano) Ronaldo or (Gareth) Bale, and bounced it in front of the keeper. Looks to me like it hit a divot and the goalkeeper made a mess of it.
"But we needed a break and thankfully we've got it. It's put us in a really, really strong position, a good position and it's in our hands with five to play."
Middlesbrough were considered strong promotion candidates themselves not so long ago. But Tony Mowbray's men have won just twice since the turn of the year in the league and have now not tasted victory in their last 10 outings on the road.
The visiting manager was left to bemoan a familiar tale as his team failed to find the net for a fourth time in their last five contests.
"I don't think there was much in the game," said Mowbray. "From my eyes I thought we were probably the better team on the day, probably created more chances. I thought it was a tight game, not much in it."
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