Briton Adam Yates stretched his Tirreno-Adriatico lead as Jakob Fuglsang won the fifth stage.
Mitchelton-Scott's Yates finished 40 seconds behind Astana rider Fuglsang on the 180km hilly stage to Recanati.
But the 26-year-old added 18 seconds to his overall lead and now holds a 25-second advantage over Primoz Roglic, who finished third on Sunday.
Dane Fuglsang dedicated the win to his former team-mate Michele Scarponi, who was killed in a training crash in 2017.
Scarponi grew up in nearby Filottrano and the fifth stage of the 2018 Tirreno-Adriatico was dedicated to him.
"I wanted to win this stage for Michele Scarponi and his wife who visited us yesterday," Fuglsang, 33, said.
Yates described the fifth stage as the "hardest of the race".
"I came close to the win but Fuglsang was on another level. I did the best I could," he added.
Monday's penultimate stage covers 195km from Matelica to Jesi.
Elsewhere, Egan Bernal held on to secure Team Sky's sixth victory in eight years at Paris-Nice as Spain's Ion Izagirre soloed away to win the final stage.
Nairo Quintana went on a long-range attack to try and overhaul Bernal's lead but was reeled in by his fellow Colombian and could only gain four seconds at the finish in Nice.
Bernal, 22, took the title over Quintana by 39 seconds, with Team Sky team-mate Michal Kwiatkowski third overall.
He is the fifth Team Sky rider to win the prestigious stage race, following Bradley Wiggins, Geraint Thomas, Sergio Henao and Richie Porte, who won it twice.
Tirreno-Adriatico stage five result
1. Jakob Fuglsang (Den/Astana) 4hrs 39mins 32secs
2. Adam Yates (GB/Mitchelton-Scott) +40secs
3. Primoz Roglic (Slo/Team Jumbo-Visma) +56secs
4. Tom Dumoulin (Ned/Team Subweb) +1min 39secs
5. Thibaut Pinot (Fra/Groupama-FDJ) +1min 53secs
Tirreno-Adriatico general classification
1. Adam Yates (GB/Mitchelton-Scott) 20hrs 33mins 48secs
2. Primoz Roglic (Slo/Team Jumbo-Visma) +25secs
3. Jakob Fuglsang (Den/Astana) +35secs
4. Tom Dumoulin (Ned/Team Sunweb) +1min 55secs
5. Julian Alaphilippe (Fra/Deceuninck-Quick-Step) +2mins 34secs