The 24-year-old led after the first day's stages and ensured he maintained his grip on first place on Friday.
"I just wanted to get through it when there was so much going on. I extended my lead, so it's been a fantastic day," Solberg said on TV4 Play's broadcast.
The Swede is 1 minute 8.4 seconds faster than Briton Elfyn Evans and 1 minute 14.9 seconds ahead of reigning world champion Sébastien Ogier of France.
"He doesn't talk to me much anymore... but there's a long way to go," the Swede said jokingly about his relationship with teammate Ogier.
The competition in Monte Carlo ends on Sunday.
