Eubanks is no spring chicken but after finally making it into the Wimbledon main draw for the first time this year, he ensured he enjoyed a run to remember as he made it into the quarter-finals of a Grand Slam for the first time with a rousing win over the Greek maverick.
Tsitsipas, who was in action for the seventh day running after having to put up with numerous rain disruptions during his matches, was bidding to become the first Greek man to reach the last eight at the All England Club.
He played his part in the highly entertaining encounter, often picking himself up off the ground to hit a winning shot.
But he met his match in the six-foot-seven Eubanks, whose cheering squad included his occasional mixed doubles partner Coco Gauff (19).
Tsitsipas broke back to level for 3-3 in the final set but he could then only watch in awe as Eubanks hit a stupendous backhand down the line in the next game to again nose ahead 4-3.
With the finishing line in sight, Eubanks belted down his 12th ace to bring up match point and a rip-roaring forehand winner finished off the job.
He will next face Russian third seed Daniil Medvedev (27).