The former Team Sky and BMC rider dropped the Movistar rider on the final climb of the Trofeo Andratx - Mirador d'Es Colomer and held him off in the final metres.
The grainy video, above, shows Cummings on his team issue Cervelo looking back to make sure that Valverde wasn’t on his wheel before crossing the line.
"I felt really really good," Cummings told Cycling Weekly at the finish line. "I had a really good winter and I knew the final climb because with the British team ten years ago we used to come and do this climb five times a day.
"I knew I had to go with one kilometre to go because Valverde is too strong in the final."
Cannondale-Garmin rider Davide Formolo held off Trek Factory Racing’s new signing Bauke Mollema to claim third place in a sprint to the line.
Team Sky’s Leopold Konig, who joined from NetApp-Endura after his seventh-place finish at the Tour de France, rolled home in fifth.
The win is Cummings' first since February 2014, when he took the 18km time trial at the Tour Mediterranéen, seeing him win the General Classification as well.
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