New Delhi, April 7 : Dominic Thiem produced his best performance of the season at the Millennium Estoril Open where he cruised past Ben Shelton 6-2, 6-2 to reach his first quarter-final of the year. The Austrian earned a confidence-boosting victory against countryman Sebastian Ofner in the first round and backed that up with a dominant display against Shelton. He crushed the ball off both wings to overpower the American, earning consecutive tour-level wins for the first time since he advanced to the semi-finals in Antwerp in October, reports ATP. The former World No. 3 will aim to continue his run when he takes on fourth seed Roberto Bautista Agut or Quentin Halys in the last eight. Thiem is up eight spots to No. 103 in the ATP Live Rankings and will crack the Top 100 again if he reaches the semi-finals in Estoril. Thiem holds a 3-8 record for the year after Thursday's win, which he will hope is the catalyst for improved results. The Austrian, who reached the Roland Garros final in 2018 and 2019, has historically excelled on clay. He has won 10 of his 17 tour-level crowns on the surface. Shelton this week was making his tour-level debut on clay. The 20-year-old, currently No. 39 in the Pepperstone ATP Live Rankings, has enjoyed a standout start to the season, highlighted by his run to the quarter-finals at the Australian Open. Later on Thursday, Spain's Bernabe Zapata Miralles earned a comeback victory against second seed Hubert Hurkacz, 6-7(7), 6-4, 6-2. By beating the World No. 12, Zapata Miralles scored his biggest career win by measure of the Pepperstone ATP Rankings and picked up his second Top 20 victory after beating Taylor Fritz last year at Roland Garros. Hurkacz fell short of what would have been his 27th tour-level quarter-final and his third on clay; he reached the last eight in both Monte Carlo and Madrid last season. Zapata Miralles will meet Miomir Kecmanovic in the quarters after the Serbian cruised past Austrian Jurij Rodionov 6-0, 6-1 to continue his perfect debut week in Estoril. The sixth seed was ruthless throughout the 64-minute encounter at the clay-court event, pulling the World No. 120 around with his dynamic shotmaking to reach his third quarter-final of the season. Kecmanovic has not lost a set in his two Estoril victories, beginning with a straight-sets win against Luca Nardi in the first round. /IANS