"It was a good work out, especially for those guys making their first start on the tour. We put a few combinations together and some of the guys are still a bit tired from the flight, but we got up to speed in terms of preparation pretty quickly," Gatland told Sky Sports.
"Overall, we're pretty pleased - it's just getting used to the interpretations of southern hemisphere referees. I'm not criticising him, it's just the players adjusting to having one crack at the breakdown - there are still a few things to work on, but overall pretty pleased.
"We talked about keeping the pace and at half-time being ruthless and finishing them. When we got down there we kept our composure, took our points and didn't miss too many opportunities.
"Defensively we made one or two errors but we'll work on those around the fringes. That's an area Australia are going to come pretty strong at us so we'll tidy that up but overall it was pretty satisfactory.
"The chat today was about being ruthless. It was about us and playing for 80 minutes. It's easy enough to fall off the intensity in the last 10 or 15 minutes but it was about playing for the full 80.
"You always want to play against the strongest sides and that's a concern for us at the moment. We need to make sure if we're not given it on the field, we replicate it in training.
"A big lesson we learnt from 2009 was we arrived at the first Test and we hadn't played strong enough sides. We have to make sure that intensity we will meet in Brisbane in the first Test is there. If we're going to have games like tonight we will have to do a bit extra."
The clash with the Reds is likely to be one of the biggest challenges the Lions will face before the first Test as they go in search of their first win over the tourists since 1971. It will also be the final opportunity for Quade Cooper to push his claims for inclusion in the Qantas Wallabies squad.
But if the Lions can continue to take the points in the manner they did in Perth then their chances will be greatly enhanced.
"I thought the goal-kicking was pretty special. He didn't get many easy ones - 11 out of 11 is pretty special," said Gatland in praise of full back Leigh Halfpenny.
"Overall I was pleased with the performance and the guys coming off the bench. There were some really good things and the guys coming off the bench are giving us really good momentum to carry on. If you look at the squad now, the challenging thing for us is picking that starting XV for the first Test - it's looking very healthy for us."