Carlos Sainz, twice a winner, took immediate advantage of Makinen's spin on the day's first special stage, taking over first place in his Toyota Corolla.
Makinen led his Spanish rival by more than a minute after Monday's first six stages but said: "I always said anything could happen in this rally."
He is to undergo tests in a Helsinki hospital today as Makinen appears to be "still suffering from the after-effects of pneumonia," according to a Mitsubishi spokesman.
The Monte Carlo is proving something of a mountain for Makinen, who has never won the rally. He was leading last year when the wrong choice of tyres on the final overnight stage cost him victory.
His countryman Juha Kankkunen, four-times a world champion, moved up to second place in a Ford Escort after the first two of yesterday's stages.
The Subaru drivers Piero Liatti, of Italy, and Britain's Colin McRae recovered from minor setbacks to exert pressure on Sainz. Liatti, last year's winner, had rolled his car over in the day's second special stage when McRae punctured but they both fought back in the next stage to reduce Sainz's lead. Richard Burns, driving in his first Monte Carlo, was an impressive third, 1min 28sec off the pace, in his Mitsubishi, ahead of Liatti and McRae.Reuse content