World No 1 Jannik Sinner brushed aside Britain's Cameron Norrie 6-2 7-5 on Tuesday to book a place in the Madrid Open quarterfinals, stretching his ATP Masters 1000 winning streak to 25 matches as the players avoided the worst of the heat.
The match at 11am local time meant they started in cooler conditions but Madrid is on red alert for allergies, with record pollen levels not seen in 45 years drifting across the Caja Magica, the tennis centre in the southwest of the capital.
Yellow and white grains have swirled and settled on the clay for several days, at times coating the courts and irritating eyes and throats but Sinner showed little sign of discomfort.
The Italian, still seeking his first Madrid title to complete a notable gap in his trophy cabinet, wasted no time asserting control. He raced through the opening set in 35 minutes, giving Norrie scant opportunity to settle.
The Briton tried to change the script in the second set but was under constant pressure. Sinner had two break points in the fourth game and soon broke for 3-2 after Norrie's underarm serve trickled into the net, drawing boos from the crowd.
Norrie, seeded 19th, responded immediately, breaking back to level at 3-3 and briefly reignited the contest.
He held firm until the 10th game, where a double fault handed Sinner two more break points. Norrie saved both to reach deuce but Sinner quickly carved out another opportunity, which he converted to edge ahead 6-5.
From there, the top seed kept his composure, wrapping up the contest in one hour 26 minutes.
"I'm happy with my performance," Sinner said. "I tried to be a bit more aggressive and I believe it worked very well for me against a very tough competitor. So I'm happy to go ahead in two sets and ready for the next round."
Sinner will next face either Czech Vit Kopriva or 19-year-old wild card and Madrid native Rafa Jodar.