Max Verstappen's glowing second half of the Formula 1 season was enough to see him end 2018 as the grid's top performer – perhaps even ahead of champion Lewis Hamilton – according to the Mercedes man's former teammate and rival Nico Rosberg.
Verstappen spilled points as a result of driving errors in five of the opening six races of the season -matters coming to a head when a practice crash in Monaco denied him the chance to compete in a race that Red Bull teammate Daniel Ricciardo won in dominant fashion.
However, the Dutchman responded superbly, taking to the podium in 10 of the subsequent 15 races and showing the kind of performances that have billed him a champion-in-waiting.
Rosberg was among those critical of Verstappen in the early months of the campaign, but hailed his stunning turnaround.
"He showed he learnt from those mistakes at the beginning of the season, the speed was always there," Rosberg said on Sky Sports.
"In the second half, he's put it all together and maybe he's been even the best driver out there.
"He's done a phenomenal job, the car has improved as well so the package is better. It's been really fun to watch."
Rosberg believes Verstappen could emerge as a genuine title challenger in 2019, although it all depends on Honda's ability to put Red Bull in position.
He added: "It takes a while to learn unless you're Lewis Hamilton.
"He's been growing a lot, he's just a little on the edge too much all the time.
"He has to reel that bit a little bit, he's understood that. If he's got the car next year, he can be a contender for the championship."