Lee Westwood and Darren Clarke shot rounds of 66 and 67, respectively, to move to within three shots of Romero through 36 holes at Crans-sur-Sierre, Switzerland. Romero, who hasn't won since capturing this event in 1994, carded a 3-under-par 68 on Friday to climb to 10-under-par for the tournament.
Westwood and Clarke, ranked first and second on the current Order of Merit, are tied with Australian Jarrod Moseley and Hennie Otto at 7-under. Thomas Bjorn, who stands in fourth place on the 2000 European money list, is just four shots off the lead after carding the round of the day, a 7-under-par 64.
Bjorn started the day at one-over-par, but began Friday's back nine 2,4,3,2 - five-under-par for four holes. At 6-under for the tournament, last year's runner-up is one shot clear of Welshman Phillip Price, who tied for second at the WGC - NEC Invitational two weeks ago.
With the strong contingency behind him, Romero isn't resting on his three-shot cushion. Friday, Westwood nearly caught the Argentine, but a combination of three birdies in the last four holes by Romero and a closing bogey by the Englishman, increased Westwood's 36-hole deficit to three.
'You can blow your chances on the first two days and I haven't done that,' said the defending champion, 'even though I again didn't hole one putt.'
While Westwood is happy with his position through two rounds, Clarke is not. Said the Northern Irishman: 'I gave myself so many chances, but 32 putts for a 67 is very poor.
'It was a combination of the greens and my poor putting. I've missed so many times from inside five feet already this week.'
Michael Campbell began the day one shot off the lead, but posted a 3-over-par 74 in the second round to fall into a tie for 10th at 3-under.