Australia's Kurtley Beale had two late opportunities to snatch victory for the hosts, but the Lions held on to secure the win in the first Test in Brisbane.
"It was a tough game. The first half we scrummaged well and our line-out went well but I'm a bit disappointed in the game management. We've got in front and then given a couple of soft three-pointers to let them back in the game," Gatland told Sky Sports News following the match.
"It just shows how close this series is going to be. We saw some great tries out there tonight. We're pretty happy. It could have gone either way but we'll take that and we think we deserved to win. We'll work on our performance but what matters is the result. We probably played a bit too much rugby in our own half in the first half. It was better in the second. It wasn't the greatest Test in the world but we've won the first Test and we're really happy with the result."
"There's a great team spirit at the moment. The guys are working hard and selection has been tough. We're also getting back a few key players next week and that will strengthen our squad."
The Lions are next in action against Melbourne Rebels on Tuesday.