Paolo di Canio's side suffered an embarrassing opening-day defeat to notoriously poor travellers Fulham, despite dominating for the most part at the Stadium of Light.
The roles reversed yesterday at Southampton, where Emanuele Giaccherini's early header looked set to decide a one-sided clash.
Jose Fonte's goal two minutes from time eventually saw the points shared, but Gardner was pleased with the Black Cats' performance.
"We expected them to throw everything at us," the midfielder said. "They were at home for the first time in the season.
"We expected that and against Fulham we did absolutely everything apart from find the net.
"We came here and I thought we did really well. Yeah, they were on top but they never really broke us down.
"I thought we defended brilliantly as a team and the 2,000 Sunderland fans that came down were absolutely unbelievable as well, singing their hearts out.
"Hopefully they can understand we came here with a game plan and got a result. We got the one so we can look onwards and upwards now."
Sunderland looked a surprisingly strong team unit considering the number of transfers in and out this summer.
Di Canio has so far signed 11 players and more are on the horizon, but, while still a work in progress, Gardner has been impressed by the early signs.
"We work day in, day out on the training field," he said.
"Each game comes and we have got a different tactic to approach the game and - only time will tell but - I think we will be fine."
The draw at Southampton was an impressive response to Sunderland's opening weekend defeat.
For Saints, though, it was a case of what might have been after winning at West Brom.
"It was a little frustrating," striker Jay Rodriguez said. "We created enough chances to get the three points but in the end it was a good point obviously being 1-0 down.
"The first goal must have been due to a lack of concentration. We work on that a lot and it is just an easy goal to give away, which is what is really disappointing for all of us."
Saints managed to grab a late leveller but the overriding feeling was one of frustration, with the home side's dominance seeing them take 17 shots to Sunderland's eight.
"I think it was maybe a bit of bad luck," Rodriguez added. "I think I should have done better with my header in the second half.
"Either side of the goalkeeper it would have been in, but that is just how football goes sometimes.
"It is good that we are creating chances and next time we just need to put them away."