Lutsenko, 25, has all but won the tour after crossing the finish alongside Lopez, who after the one-two punch is second overall before today's final flat dash for the sprinters.
Australian Nathan Haas (Katusha-Alpecin) proved he had reason to believe in his climbing legs, coming in 22 seconds down on the winner to stay within the top five overall.
Astana effectively formed its own escape on the early slopes of Green Mountain with the Bahrain-Merida jersey of Gorka Izagirre an anomaly in the four-man attack.
Lutsenko and Lopez survived to the top, saluting each other over the finish where team general manager Alexander Vinokourov was waiting to congratulate them.
"We knew that this stage would decide the general classification so we were really motivated. We controlled the race from the start, the guys worked really hard from kilometre zero until the last 2km to go where we still had three riders in front," Lutsenko said under a baking hot sun.
"The main goal for us was to win the stage. Together with Miguel Angel Lopez, we did our best to get some time from the rivals and win. The team was super strong today."
The undulating road at the start in Sama'il flattened out to wide, open space for kilometres as a six-man break, including Australian Nicholas Schultz (Caja Rural-Seguros RGA), achieved a maximum time gap of about five minutes.
The race came together at the base of Green Mountain, as the escape began to disintegrate and the peloton charged.
Lutsenko said he and Lopez were honest about who would take the stage as they rode together to the finish.
"I worked a lot before the last kilometres and Miguel was stronger on the climb, especially in the final, he pulled a lot so he was in front and it was automatic. Miguel went for the victory and I followed his wheel in the last kilometre," the Kazakh said.
Jesus Herrada (Cofidis) finished the penultimate stage third, reaching immediately for the ground as he crossed the line ahead of Izagirre.
Both Cofidis and Bahrain-Merida recorded casualties from minor crashes throughout the stage. Antonio Nibali winced in pain as a team soigneur poured water over cuts and abrasions to his arm and side. French sprinter Nacer Bouhanni was also dusted up.
The Tour of Oman includes tomorrow with stage six - a 135.5km run from Al Mouj Muscat to the picturesque Matrah Corniche.