The striker's first-half penalty was enough to settle a fiercely-contested occasion at Villa Park and lift Saints above their opponents in the Barclays Premier League table.
After dominating the opening period and taking a deserved lead, Lambert and his teammates faced a barrage of attacks from the hosts after the break.
But they held firm, leaving the striker delighted with his afternoon in the Midlands.
"We're grinding out results," Lambert told Saints Player
at full time. "It might not have been one of our best performances today, but it was an important result.
"I was happy to see my penalty hit the back of the net, and for it to be the winning goal is even better. I thought we played very well in the first half and it was only a matter of time until we were going to score, whether that penalty went in or not.
"We came out thinking we were going to push for a second, but we were disappointed with our second-half performance.
"Full credit to Aston Villa for pushing us back. They did put us under pressure, but I'm just concentrating on our boys and our performance.
"I thought we were terrific – the performance might not have been so good, but we stuck in there and battled away.
"The defenders were brilliant again," he added after Saints recorded their first away clean sheet of the season.
"We've adapted because we had a hard start and our defensive record wasn't good. People were saying all kinds, but we knew we had good players and they would adapt – and they've shown that now. Full credit to them because they've been superb over the last few weeks."
Lambert says that today's result in a testing occasions will give the side confidence ahead of Wednesday's visit to European champions Chelsea.
"This was a hard game physically, but the lads are fit and very confident now," he said.
"It's brilliant at the moment. We are going really well and picking up points against the teams around us, which is massive come the end of the season.
"We still know there's a long way to go, so we've got to take our run of form into Wednesday because we know how hard that's going to be. Let's hope we can get something."
The striker – now on nine goals for the season – also lavished praise on fellow striker Jay Rodriguez.
"With any partnership, it takes a little bit of time to gel," Rickie said of how he linked up with the summer signing.
"We're still learning each other's gams, but Jay is a terrific player. Every time I got the ball, I was looking for Jay because his runs and his movement are superb.
"You could see how much damage he caused them in both halves, especially in the first. He's superb in training and in games, and he's still a young lad as well.
"He's going to improve and there's a bright, bright future for him. I'm enjoying playing with him."