Lewis Hamilton says he won't be drawn into a "childish war of words" with Max Verstappen after the Red Bull driver's victory in the Monaco Grand Prix - but the tensions are clearly rising between the two favourites for the world title.
Verstappen's triumph on the streets of Monte Carlo on Sunday took him to the summit of the Formula One standings for the first time in his career after Hamilton, hampered by a poor Mercedes strategy call, finished a lacklustre seventh.
Red Bull also took charge of the constructors' championship.
In the build-up to the fifth round of their spellbinding title battle, Hamilton lit the touch paper in his rivalry with Verstappen by claiming the Dutchman has a lot to prove.
Red Bull team principal Christian Horner then suggested Verstappen is getting under Hamilton's skin - and in the moments after dancing his way to victory on the sport's most famous streets, the new leader couldn't resist a barb.
"Actions always speak louder than words," he said, signing off from his winner's press conference. "That's a good lesson after this weekend.
"You only have to talk on the track and that is what I like. We as a team so far made the smallest mistakes. That's why we are ahead."
Responding to his rival, Hamilton said: "I am not playing mind games. It is interesting what Christian comes out with, but I couldn't care less. They did a great job this weekend and that's that.
"There are 17 races to go. I'm not going to say more. It's childish when you start getting into a war of words."
Verstappen, who started from the front after pole-sitter Charles Leclerc was ruled out of the race following a mechanical failure, led virtually every lap on his way to a crushing victory in the principality.
Hamilton pointed the finger at his team after losing two positions during the opening round of pit-stops.
"It was not a great weekend but I don't feel like I am dwelling on it," added Hamilton, now four points behind Verstappen.
Verstappen crossed the line 8.9 seconds ahead of Ferrari's Carlos Sainz, with Lando Norris claiming the third podium of his career following another fine drive to finish third.
But Norris's Australian teammate Daniel Ricciardo had another tough afternoon, coming home only 12th.
Verstappen's path to glory was effectively sealed when Leclerc retired from the race before it had started.
Ferrari elected not to change the Monegasque's gearbox following his 110mph crash in the closing seconds of qualifying on Saturday.
The decision ensured Leclerc escaped a five-place grid penalty, but it backfired after he reported problems immediately upon leaving his garage.
"No, no, no, no, the gearbox, guys," said a slowing Leclerc over the radio as he emerged from the tunnel.
He made it back to the pits but was unable to take up his grid slot after Ferrari identified a left driveshaft failure.
Leclerc, raised in an apartment which overlooks the start-finish straight in Monte Carlo, appeared on the brink of tears as he was told his race was over.