A two-hour delay on Thursday following days of persistent rain meant 18 players returned to the Royal Park I Roveri course to complete their opening rounds on day two.
None of those 18 were initially able to join overnight leaders Paul Lawrie, Robert Rock, Graeme Storm and Marcus Fraser, while further light rain on a saturated course also ensured the leaderboard remained tightly packed as the second round progressed.
Jiménez, the second-highest ranked player in the field, began the day at three under par but was one over for the round before kickstarting his challenge for a 17th European Tour title in style with an eagle on the par five 18th.
The 46 year old from Malaga, winner of the Omega Dubai Desert Classic in February, then picked up another shot on the first to move to five under par and into a share of the lead.
Rock, Storm and Fraser were all among the later starters, but former Open Championship winner Lawrie was level for his round after 13 holes following two birdies and two bogeys.
The 41 year old from Aberdeen, without a European Tour win since 2002, had briefly led on his own when he birdied the 11th - his second hole of the day - but dropped shots at the 13th and 16th to be out in 37 before picking up a shot on the fourth.
Jiménez picked up further shots on the fourth and fifth, the former after a superb fairway wood on the 208 yard par three, to move to seven under par.
That was good enough for a two shot lead with Lawrie dropping a shot on the ninth, his final hole, after missing the fairway from the tee and being forced to pitch out.
Asked how frustrated he was after carding a 73 to lie four under, the former Open Champion said: "On a scale of one to ten, about 15.
"I played much better than yesterday from tee to green but just couldn't get the ball in the hole and any poor shot I hit I got punished severely.
"It was the polar opposite of yesterday. I hit an awful lot of good shots and missed a lot of putts but there's not much you can do. You're going to get days where you don't get what you deserve and vice versa."