An Byeong-hun of South Korea and Scott Jamieson of Scotland moved within one shot of the lead as the weather-delayed first round of the Italian Open was completed on Friday.
Shooting 6-under 65s, An and Jamieson tied for second with local favorite Francesco Molinari behind defending champion Rikard Karlberg of Sweden.
Karlberg and Molinari finished their opening rounds on Thursday at the Golf Club Milano, next to Monza's Formula One circuit.
Masters champion Danny Willett made a strong start to his Ryder Cup preparations with a 66 and was tied with five other players two strokes back.
More than half of Darren Clarke's Europe team is competing in Monza with the Ryder Cup scheduled for Hazeltine in Minnesota at the end of the month.
The second round was getting underway on Friday.