Pablo Larrazabal birdied four of the last six holes to go three shots clear after the third round of the BMW International Open in Germany.
The Spaniard has still to drop a shot at Gut Larchenhof after following up blemish-free rounds of 69 and 63 with a five-under-par 67 on Saturday to move to 17 under for the tournament.
There was also an unexpected late bonus for the 31-year-old - whose tee-off time was delayed by an hour and 40 minutes due to the threat of lightning - as rival Emiliano Grillo double-bogeyed the par-four 18th .
Argentinian Grillo, one of four joint overnight leaders alongside Larrazabal, Rafa Cabrera-Bello and Danny Willett, was just one shot behind Larrazabal going up the last but his slip saw him drop back to 14 under.
That left Grillo in a group of eight players in joint second spot who will be hoping to put Larrazabal, the 2008 Sir Henry Cotton Rookie of the Year, under pressure on Sunday.
Among them is Richard Green after he produced the lowest round of the week to power up the standings, the veteran Australian carding eight birdies and an eagle in his 10-under-par round of 62 .
There was little sign of the fireworks to come as Green reached the turn in 34 after birdies on the first and fifth, but he then went on a stunning run to come home in just 28 shots.
Alongside Green and Grillo on 14 under are world number two Henrik Stenson (66) and his fellow Swede Robert Karlsson (68), Spanish duo Carlos del Moral (66) and Cabrera-Bello (70), Dane Thomas Bjorn (66) and Italian Ryder Cup player Francesco Molinari (65).
There are nine players sat on 13 under, including English duo Paul Casey, who carded nine birdies in his 63, and Willett.
Willett held a share of the lead after both of the opening two roads but, on a day when there were low scores throughout the leaderboard, the Yorkshireman could record a one-under-par 71.
It might have been even worse for Willett after he bogeyed two of his opening five holes, but birdies on the 15th and 17th helped him claw things back.
The European Tour have announced that the final round will be played in threeballs with the tee times brought forward as another thunderstorm is forecast to hit late on Sunday afternoon.