Having been forced to watch from the sidelines as McLaren began their renewed Honda partnership by locking out the back row and finishing two laps down in Australia, Alonso said their form at Sepang - and the improvements they had made in just two weeks - had been pleasantly surprising.
"This whole weekend has been better than I expected," the Spaniard reflected after a race in which he ran as high as eighth before engine gremlins forced him to retire.
"The main positive to take away is the fact that we were able to run with other cars - Jenson [Button] and I weren't simply fighting with each other. That was the first step we needed to take, and we've taken it already.
"Indeed, our race pace was surprisingly good; I was running with the pack, and I was even able to catch the Red Bulls before the pit-stops. That was a nice surprise.
"We still need a little more time to investigate the exact cause of my retirement. The team came over the radio to tell me to back off a little, to save the car, so I brought it back to the pits.
"For us, these are the sort of reliability problems you'd usually discover in pre-season testing, but, given our lack of running over the winter, unfortunately we're likely to encounter such issues in the first few races of the year. Hopefully, we can take another step forward in China."
Button echoed his team mate's sentiments, despite himself retiring with turbo issues.
"I enjoyed it out there - we're actually racing people," the British driver said. "To be able to see one of the Red Bulls ahead of me - and so far into the race - was obviously a nice surprise. And we were able to mix it with the others a little bit more, too.
"Fighting in the pack is the most positive thing to take away from this weekend – hopefully, before too long, we can start to pick them off on a race-by-race basis."
McLaren's best lap of the race was a 1m 46.056s set on lap 38 by Button, which put him 16th on the list of 19 drivers, four seconds shy of Nico Rosberg's leading time of 1m 42.062s for Mercedes.