Ireland's Paul Dunne has held onto a one-shot lead of the Spanish Open after shooting a 4-under 68 through the third round in Madrid.
"I can't remember a round where I've hit it tee to green as good as I did today", said Rahm, who finished fourth in the Masters on Sunday. "The putts that missed I didn't leave myself much to do and the good putts always looked like they had a chance of going in".
Dunne will have to fend off the challenges as a couple of home favourites as local superstar Jon Rahm is now on -15 and only two shots behind the leader.
"I find the greens quite tricky to read, especially on the front nine, so it was nice to get a couple of putts to go in on the back nine and climb up the leaderboard", Dunne, who won the British Masters previous year, told Sky Sports.
Warren also slipped four shots behind Dunne in a four-man group with Rahm, Englishman Robert Rock and Swede Henric Sturehed, while holder Andrew Johnston carded a four-under to finish five shots back in a six-way tie for ninth.
A tap-in birdie from Dunne at the 12th was cancelled out by Elvira getting up-and-down from the bunker to make a close-range gain at the next, with the Spaniard adding another from five feet at the 16th to halve the deficit.
"I probably wouldn't have taken it at the start of the day but given the shots that I hit, I'm pretty happy with it leading into tomorrow". Things like that are obviously a bonus.
He was inches away from responding with an eagle on the par-5 18th, but his long putt stopped dead agonisingly short of the cup.
Elvira is looking for his first European Tour win in his fifth full season on Tour.
"It is a good start in a great tournament", Pastor said. "It gives you a good day and the next day is terrible". "My golf was good so I'm really happy".
Dunne has topped the leaderboard since the opening day but saw his advantage narrowed from four shots to one over Elvira after finishing the day with a four-under 68, his poorest showing so far at the Centro Nacional de Golf in Madrid.