Lopez came out triumphant after another two hours and 49 minutes of combat.
The match between 37-year-old Lopez and 18-year-old Auger-Aliassime marked the largest age difference in an ATP Tour semifinal or final since Hong Kong in 1977, when Ken Rosewall (43) defeated Pat Dupre (23) in the semifinals.
"I asked singles players who had already committed to playing doubles, and they didn't want to commit to playing in three events, which I completely understand because it's a lot".
Both singles semi-finals were absorbing in their own way, while the doubles that followed was filled with tension and excitement.
Lopez broke back immediately and it stayed with serve before a tie-break which featured a 33-stroke rally.
Lopez played three matches on Saturday, starting by booking his place in the singles final with a hard-fought win over Canadian teenager Felix Auger-Aliassime over three sets.
"I'm so happy to have Andy playing with me".
Murray and Lopez had only just completed their 6-4, 7-6 (7-3) quarterfinal win over British duo Daniel Evans and Ken Skupski after that had been delayed by darkness the night before. I felt very relaxed at the beginning of the week and was getting more nervous as the week went on and my competitive instincts kicked in. "I would never have imagined I could reach the final of Queen's at 37 years old". It was tough for Feli and he has another final to play in a few minutes. "I was feeling the ball great, even if I wasn't feeling great in the legs". That's what I do. "And I do it for long", Simon told reporters.
Murray said: "I think things have probably got a little bit better with each match".
Medvedev, clutching his back and leaning on his racket at times, looked a spent force and a double-fault cost him his serve at 3-4.
Simon sealed victory in emphatic style to become the first French finalist here since Jo-Wilfried Tsonga in 2011.
The three time Grand Slam singles champion said he felt "as well as I did there, not ideal in terms of my movement".
After winning the first set, Bencic served for the match at 5-4 in the second but squandered several chances to win the tournament. It was more whether adrenaline could carry Lopez through one more match.
Lopez wasted a match point in the 12th game of the contest but a sensational lunging backhand volley put him 5-2 ahead in the deciding tiebreak and he made no mistake the second time. The pair produced a series of fine shots in the championship tiebreak and were able to wrap up the decider 10-5.
"It was a good match".
"It was an unbelievable effort from Feliciano".