Lewis Hamilton believes Mercedes still have their work cut out to beat Max Verstappen and Red Bull, despite the victory in an eventful Russian Grand Prix that took him back to the top of the Formula 1® standings.
Reigning title-holder Hamilton leads Verstappen in the drivers' championship by two points after claiming his 100th F1® triumph in Sochi.
Hamilton passed McLaren's Lando Norris, who was eyeing a maiden victory from pole position, to become the first driver to reach a century of wins.
Norris spun off the track while leading with three laps to go as rain caused late havoc, Hamilton's British compatriot finishing seventh as Verstappen was able to secure second place having started at the back of the grid.
"What a race the weather provided. It's taken a long time to get to 100, and I wasn't sure it would come," Hamilton told Sky Sports.
"Lando did such an amazing job, he had incredible pace and is doing such a great job for McLaren. It was bittersweet to see my old team ahead, and they're doing fantastically."
Hamilton made amends having been disappointed with a qualifying performance that saw him start fourth on the grid, though he remains naturally wary of the threat posed by Verstappen.
"Going to bed last night I was not the happiest with the job I did yesterday," Hamilton said.
"I watched the replay and they were subtle mistakes but not ideal. I was so determined when I woke up this morning, and I was determined to just do the best job I could. I lost a lot of ground at the start trying to stay out of trouble.
"Max must have done a really great job to come up to second from last. We've got our work cut out.
"It would have been tough to get past Lando unless we came up to some traffic or he made a mistake, which he hasn't been doing, so then the rain came and it was very opportunistic."