McLaren, with struggling Williams, were the two teams who did not record a single point in the season-opener in Melbourne. But Lando Norris drove very well in Q3 and ensured an eighth-place start for McLaren.
Norris' drive recorded the team's best qualifying result since 2014, and also it was the first time since 2018's Monaco Grand Prix, that a McLaren driver has made it into the top 10 in qualifying.
For Sainz, his first weekend for McLaren didn't go to plan - with the Spaniard eliminated in Q1 after a power unit problem and then being held up by Robert Kubica in his damaged Williams. But Sainz left Australia feeling positive about the Woking-based team's progress.
"The team ended last year far from the midfield, like three or four tenths and it looks like we've put ourselves back in the mix after the winter, which shows the incredible job that the team and factory has done over winter testing," Sainz explained to Crash.net.
"After Barcelona (pre-season testing), we were not so sure that Q3 was possible but I think (Australia) has proved since the first laps in Q1. For me, particularly in Q1, I felt that we maybe had a chance, maybe it's happening, maybe we can get McLaren back to Q3.
"I think it's since Monaco last year that it didn't happen. So, it just shows the progress the team is making. It doesn't mean we're going to be in Q3 in Bahrain or China, it means that we have got ourselves back in the mix. And it's now it's a matter of nailing the laps, nailing the procedures, nailing the set-ups for each track because the midfield is as tight as always."