Marc Warren and Paul Dunne finished their first rounds with a flourish to lead the Open de Espana, while Jon Rahm and amateur Victor Pastor are just one shot off the pace in their homeland.
Warren, without a victory on the European Tour since 2014, birdied five of the last seven holes to start with a six-under 66 at Centro Nacional de Golf on Thursday.
The 37-year-old has failed to finish in the top 50 this year, but made just one bogey at the fourth and raised his game on the back nine to take over at the top of the leaderboard in Madrid.
Dunne matched Warren's opening round when he went out later in the day, the Irishman conjuring up an eagle at 18 after making three of his five birdies on the back nine.
Rahm arrived on home soil buoyed by a fourth-place finish in the Masters last weekend - his best showing in a major - and put himself firmly in contention to claim a first professional title in Spain.
The world number four hit the turn in 34 after starting on the back nine, an eagle three at 18 putting a spring in his step following his solitary dropped shot at the previous hole.
Rahm - who spent two years practicing on the course earlier in his career - made further gains at the third, fifth and seventh in a strong start to his challenge.
Pastor, 113th in the Amateur Golf Ranking, started with an eagle and came up with five birdies before a bogey at the last cost him a share of the lead.
Jason Norris, Jonathan Thomson, Julien Guerrier, Erik van Rooyen and Matthias Schwab are also just a solitary shot behind the leading duo on five under along with Alexander Bjork, Henric Sturehed, Callum Shinkwin and Aaron Rai.
Andrew Johnston, 2016 winner and defending champion as the tournament was not on the European Tour schedule last year, is among nine players a further stroke back.
|What we learned from NBA All-Star Saturday|
|Kaepernick´s attorney tips Patriots to make move for QB|
|Tebow: I told Murray to follow his heart|
|Mourinho created unhealthy atmosphere – Sanchez|
|Santa Cruz defends belt against Rivera|
|Opelka, Isner set ATP Tour record at New York Open|
|Diallo soars over Shaq to win Slam Dunk contest|
|WATCH: Diallo dunks over Shaquille O´Neal|
|Silver: NBA trade requests should stay behind closed doors|
|´It´s more of an aspiration´ – LeBron clears up potential NBA ownership|
|Harris wins Three-Point contest ahead of Curry|
|Thomas leads rain-delayed Genesis Open|
|Tatum wins NBA Skills Challenge with stunning half-court shot|
|Robben: Anfield is the worst stadium|
|Valverde not nervous about Messi penalties after spot-kick miss|
|Sanchez ´worried´ amid Man United struggles|
|Schoeman hat-trick sees Lions past Jaguares|
|Piatek lives to score goals - Milan striker´s brilliant double pleases Gattuso|
|Lyon will punish Barca in this form, Pique warns|
|Guardiola lauds Silva´s ´incredible´ FA Cup performance|
|Clermont hit the top, Perpignan finally win|
|Schwartzman saves match point to down Thiem in Buenos Aires|
|Leinster withstand Zebre test as Connacht claim big win|
|Antonio Brown: Roethlisberger has owner mentality and you can´t call him out|
|Pizarro becomes Bundesliga´s oldest ever goalscorer|
|Wawrinka ends 20-month wait for final to book Monfils showdown|
|Barcelona 1 Real Valladolid 0: Hit and miss as Messi gets job done|
|Atalanta 1 AC Milan 3: Two-goal Piatek lands blow in fight for fourth|
|NBA, FIBA link up to start 12-team league in Africa|
|Guardiola proud of ´incredible´ City after Newport win|
|Worst pitch I´ve played on - Manchester City hero Foden unimpressed with Newport surface|
|LeBron James, Derek Jeter lead praise for retiring Yankees legend CC Sabathia|
|Durant happy for Porzingis but guarded on his own future|
|Newport County 1 Manchester City 4: Foden nets brace as upset is averted|
|Simeone plans Griezmann, Costa, Morata trident|
|Stephen Curry reveals three-point contest bet with brother Seth|
|Celtics, Lakers, Knicks on Anthony Davis´ list, along with 26 others|
|Mertens fights back to defeat Halep for her biggest WTA title|
|Championship Review: Norwich hit four as Baggies & Blades cruise|
|Sala mourned at funeral in Argentina|
|Costa thrilled to make Atletico return at old club Rayo|
|Specman´s spectacular debut double leads Bulls in Stormers thrashing|
|Sarries pounce on Chiefs slip as Saints sink sorry Sharks|
|Griezmann overtakes Torres on Atletico Madrid´s top-scorer list|
|LeBron James reacts to Kaepernick´s settlement with NFL: I´m happy he won his suit|
|Giannis to play for Greece at FIBA Basketball World Cup|
|Next question! - Russell Westbrook on All-Star Game team-mate Joel Embiid|
|Rayo Vallecano 0 Atletico Madrid 1: Griezmann downs derby rivals again|
|McIlroy on the charge as Tiger scrambles to make cut at Genesis Open|
|AFC Wimbledon 0 Millwall 1: Wallace knocks out West Ham conquerors|
|Lille star Leao dismisses Mbappe comparisons|
|Hamilton, Federer and Maradona send MotoGP great Rossi birthday wishes|
|Du Plessis applauds ´Superman´ Perera effort|
|Big Bash League: The best Opta facts ahead of Melbourne derby final|
|Farbrace stepping down as England assistant to take Warwickshire role|
|Spalletti hopes culprit is punished after reported attack on Icardi´s agent´s car|
|Tuchel wary of mounting PSG injury problems|
|Sangakkara, Jayawardene lead tributes to Kusal´s stunning Sri Lanka knock|
|Windies call up trio as injury replacements|
|Brighton and Hove Albion 2 Derby County 1: Knockaert strikes as Seagulls reach last eight|
|I did my part, says modest Sri Lanka match-winner Perera|
|Costa returns to Atletico Madrid squad|
|A-League Review: Perth Glory nine points clear after record defeat of Brisbane Roar|
|Ramos was asked a trick question - Solari|
|Crusaders begin with a win, Hurricanes leave it late|
|Sensational Kusal Perera inspires record-breaking Sri Lanka victory|
|Madrid´s old heads are helping Vinicius, says Solari|
|Ospina eyes South America switch as Napoli back Meret|
|I would want to be Anthony Davis, says Lakers great Abdul-Jabbar|
|Ribery future up in the air, says Bayern CEO Rummenigge|