Lewis Hamilton believes Honda's progress has brought the Japanese power unit within just 10bhp of Mercedes and Ferrari's engines.
Over the winter, Red Bull Racing ramped up its expectations for its new engine supplier based on evidence supplied by Honda.
That confidence received further validation in Australia with Max Verstappen's podium finish and Honda's flawless reliability, achievements that weren't lost on Hamilton.
"I believe it's within 10bhp or something of the top cars," said the reigning world champion.
"If you look at their GPS speed on the straights, they're pretty much just as quick as us.
"That's a great start for them and I really hope the reliability's strong for them so they can be really in the fight."
Addressing Mercedes' level of performance after its win in Melbourne with Valtteri Bottas, Hamilton felt the Silver Arrow squad had been lucky to find the optimal window of its new W10.
"We're still learning about it. As we mentioned in testing it really wasn't great to start off with. But we found a window in which it works a lot better," he added.
"We were very, very fortunate to come across that. If we hadn't discovered that in testing, we probably wouldn't have had the same results we did in the first race.
"That was really hard work from everyone collectively. It is a better car but it's not perfect, there are still areas we are working on. But it's a really great platform for us moving forward.
"We do understand the car a lot better particularly from testing, the positive two days, and obviously the race weekend. Now we're moving in a really positive direction."