Nacho Elvira, Andrea Pavan, Lee Slattery and Jeff Winther all matched the lowest opening round in D+D Real Czech Masters history to set the clubhouse target on a low-scoring day one in Prague.
Perfect conditions greeted the players at Albatross Golf Resort and the leading quad took full advantage, firing rounds of 65 to get to seven under and match the mark set by Eduardo de la Riva and Renato Paratore in 2015.
The course record of 64 had been under threat when Winther birdied the 15th to get to nine under but the Dane bogeyed his next two holes to sit in a four-way tie, one shot ahead of South Korea's Soomin Lee, English pair Eddie Pepperell and Lee Westwood, and Scot Connor Syme.
Italian Pavan and England's Slattery both arrived in the Czech capital off the back of top tens at last week's Nordea Masters, while Spaniard Elvira is also comfortably inside the top 110 on the Race to Dubai Rankings presented by Rolex.
Winther is currently 135th in the standings and a good week could go a long way towards him retaining his playing privileges for the first time.
Just 11 of the morning starters were over par, with defending champion Haydn Porteous birdieing four of his last six holes to sneak into red figures for the day with a 71.
Early leader Pavan made a birdie-birdie start and added further gains on the fifth and sixth before picking up another shot on the par five ninth.
The field kept edging back to within one but Pavan would move away with birdies on the tenth and 12th and, when he holed from 12 feet on the 13th, he led by three.
Winther was the first man to cut that gap as he started with two gains and after dropping a shot on the fourth, made five birdies in a row to turn in 30.
A wayward second and a poor chip on the 15th led to a first bogey of the day from Pavan and he was soon joined at the top of the leaderboard by Elvira.
The 31 year old eagled the par five 12th to go with birdies on the first, third, fourth, seventh and tenth to get to seven under.
Winther made gains on the 12th and 13th to get to eight under and Elvira joined him with a birdie on the 15th as Pavan parred his way home to set the target at seven under.
Slattery also moved into the clubhouse at that mark thanks to closing birdies on the seventh, eighth and ninth.
The two-time European Tour winner made birdies on the 12th, 15th, 16th and first, and bounced back from a bogey on the third with another gain before his big finish.
Winther birdied the 15th to get his nose in front but bogeyed the 16th and 17th and, with Elvira dropping a shot on the last, there was a four-way tie at the top.
Pepperell entered this week knowing a win could move him into the automatic places for the Ryder Cup Team and he made a bright start with a 66.
The Commercial Bank Qatar Masters champion birdied the tenth, 12th and 18th with a bogey on the 17th to turn in 34, before continued excellent iron play helped him pick up shots on the first, second, fourth and seventh.
Ryder Cup Vice Captain Westwood will be pleased to see Pepperell playing well and he too dropped his only shot of the day on the 17th, adding birdies on the tenth, 16th, first, second, fourth, sixth and ninth.
Syme was bogey-free in his 66, making birdies on the third, sixth, eighth, tenth, 12th and last.
Lee overcame a double-bogey on the last with birdies on the 11th, 17th, first, second, fourth, fifth, seventh and eighth.
German Alexander Knappe made the 29th hole-in-one of the season, aceing the seventh with a seven iron from 187 yards to sit in the group at five under alongside Spaniard Pep Angles, American Chase Koepka, English pair Aaron Rai and Callum Shinkwin, and Zimbabwean Scott Vincent.
