Tunnicliffe scored his side’s third goal in a fully-deserved 3-0 win over their Premier League visitors at Broadfield Stadium.
“It hasn’t sunk in yet, I don’t think,” said Tunnicliffe, who played 67 times for Harriers from 2014-17, a period which included a brief loan spell with the Pitmen in 2015. “I think shock at the minute is the overriding emotion.
“We know how good Leeds are but we knew that if we gave 100 per cent and stuck to our guns that we had a chance and I think every man (has) done brilliantly out there.
“We’ve been watching Leeds in the Premier League on TV and know how high intensity they are. We had to match that and we did and luckily won 3-0.”
Asked about his preferred opposition in the fourth round, Tunnicliffe added: “We don’t want to get too carried away, we want to go as far as we can but a giant-killing would be lovely.
“Leeds were a big club in themselves but we’d love a big club, go away somewhere and enjoy the day out.”
Nick Tsaroulla opened the scoring five minutes into the second half and fought back tears in his post-match interview.
“I’m buzzing. It was an amazing team performance. I’m getting a bit emotional now. It’s been a long hard road for me and this is a great moment. I’m really proud.”
Crawley manager John Yems hailed the performance of his players, adding: “It’s nice when you work on something and you’ve got the players here, there’s a lot of them have a lot to prove to other clubs that released them.
“It was just a really good team performance. We did what we could do. They’re a good side. We are what we are so let’s see who we get in the next round and just enjoy the moment.”
Ashley Nadesan made it 2-0 just three minutes after Tsaroulla’s opener and was named man of the match.
“Overall, it’s a team performance and every single one of us has done everyone proud today,” he said. “One person gets man of the match but every single one of us put in a shift.
“The first goal was a bit of a shock but the second one straight after gave us more momentum and pushed us on to get the third. It was an all-round performance which we’re proud of.”
Leeds manager Marcelo Bielsa admitted his side had failed to create many chances as he reflected on a hugely disappointing performance.
Bielsa said: “We couldn’t unbalance them when we attacked. We had the ball for a long period of time but we couldn’t do much with it.
“In the first half, we played better than the opponent and the game was played how we wanted it to be played, even if we did not create much danger.
“And in the second half the game was played how the opponents wanted to play and they did create danger to deserve the goals that they scored.
“The result generates a lot of sadness and disappointment for us.”
Asked if he had been surprised by Crawley’s performance, Bielsa added: “No it’s not a question of surprise. We knew the characteristics of their players and the opponents just like every other opponent.”