Hull boss Grant McCann was proud of his players after they dug deep to edge through to the second round of the Carabao Cup on penalties at Sunderland.
The Black Cats had the better of the game and created numerous good chances but Hull survived long enough and the tie went to spot-kicks after a goalless draw.
Will Grigg, who had a goal harshly ruled out in each half for a foul and an offside, missed the opening penalty before the rest were all converted to leave Hull 5-4 winners.
McCann said: “We were against a side that is used to winning and probably would have finished in the play-offs had last season continued.
“It was a tough game and I thought we showed a good temperament in the first half to not concede when Sunderland were on top of us. We defended well although we rode our luck at times.
“The second half started off a bit cagey but I thought our fitness levels showed in the last 15 or 20 minutes and we looked like the team that was going to go on and win it towards the end.
“I was pleased with the penalties. The boys showed good composure to score five out of five.
“It was a good day’s work for us. We weren’t at our best but we showed a different side to us, one that we maybe didn’t show enough of last season. The togetherness was there to get that clean sheet.
“We want to change that losing habit that we had into a winning one and we’ve started well.”
Sunderland boss Phil Parkinson was left frustrated by his team’s failure to take chances – even though he was satisfied with aspects of the display.
The home side would have scored in the first half but some wasteful finishing and decent goalkeeping from Matt Ingram kept Hull level.
Parkinson said: “We created a lot of opportunities but we were not able to take them. The energy levels, the intensity and the balance of what we are trying to do I thought we were good.
“Hull were always going to lift in the second period but I felt we were good. We should have won the game comfortably.
“Will’s second goal I have only seen briefly, he looked marginally offside. But the first one I felt should have stood, I will look again. It’s small margins.
“Will deserved his start. I thought some of his movement and his runs were great. He is fitter than he has been for a long time. He is getting into those areas, he will feel aggrieved he hasn’t got a goal.
“The penalty will hurt him. He prides himself in those pressure situations.”