Lewis Hamilton insists the challenge of retaining his Formula One world championship never gets old as he looks to create history with Mercedes.

Hamilton led from start to finish at Circuit Paul Ricard on Sunday, easing over the finish line 18 seconds ahead of his team-mate Valtteri Bottas.

The five-time F1 champion had to switch from medium to hard tyres halfway through the race in Le Castelle, though that stoppage made little difference as he claimed a fourth successive win.

With six race victories under his belt already this season, Hamilton is well on his way to defending his title with ease, but believes the real test comes in finding marginal gains after another procession to the top of the podium.

"It never gets old, it's always such a challenge out there and I just love that trying to find the edge," Hamilton said.

"I couldn't do it without this incredible team, we're creating history. I'm hyped.

"It wasn't easy at all. There's always things happening, everything's on the edge.

"Reliability is everything, I had big blisters on the front two tyres so I was a bit worried. This has been the best start so we've got to enjoy it."

Bottas sits second in the drivers' standings, with Mercedes well in front of Ferrari in the constructors' championship, and the Finnish driver lauded Hamilton's dominant display.

"Not that much happening from my side obviously," Bottas said.

"The start was the best bet for me but Lewis had a good start as well. I couldn't match his pace. He was really strong and consistent. He's not unbeatable. I just need to work hard."

Frenchman Charles Leclerc took third place, while Ferrari team-mate Sebastian Vettel crossed in fifth behind Red Bull's Max Verstappen.