The 23-year-old Everton academy graduate only arrived at the club on Friday evening but was thrown straight into the deep-end by boss Paul Hurst for the East Anglian derby against Norwich on Sunday.
With a 1-1 draw secured, the defender - who was praised for his impressive performance - says Ipswich felt like they had done enough to win the game.
“I was delighted to start and it was a great first game to come into," Pennington said.
“The fans were excellent and I really enjoyed it out there, I just wish we could have got the win.
“Overall the lads felt like it was two points dropped – we had spells where we were on top and I think we should have put the game to bed.
“That can happen in derby games, though, so we just have to take the point and move on."