SAN ANTONIO – Marc Castro remained unbeaten after turning away the physically biggest and most experienced opponent of his young career.

The unbeaten prospect wore down Tijuana’s Ricardo Lopez en route to a seventh-round stoppage victory. No knockdowns were scored in the lightweight contest but a barrage of power shots by Castro left Lopez defenseless which prompted referee Mark Calo-oy to stop the contest at 2:22 of round seven.

The bout aired as part of DAZN’s ‘Before the Bell’ preliminary show Saturday live from Boeing Center at Tech Port in San Antonio, Texas.

Fresno’s Castro made a conscious effort to target the body of Lopez, a rugged 25-fight veteran who’d fought as heavy as 152 pounds in his seven-year career. Lopez showed resilience, barely flinching in the early stages as Castro loaded up with left hooks and looping right hands downstairs as the 25-year-old Mexican would respond with straight right hands upstairs.

There were no knockdowns in the high contact affair, though Castro fell to the canvas late in round six. Referee Mark Calo-oy correctly ruled it a push as he wiped Castro’s gloves and ordered the fighters to resume action.

Castro came out swinging in round seven, drawing cheers from the crowd as he pinned Lopez along the ropes and launched a flurry of power shots. Lopez was once again in trouble and forced to clinch but quickly ran out of real estate. A follow-up barrage by Castro forced an immediate stoppage as Lopez (16-7-3, 11KOs) covered up while trapped against the ropes.

Castro picked up his deepest stoppage victory to date as the 23-year-old prospect advanced to 10-0 (6KOs).

Headlining the show, local hero Jesse ‘Bam’ Rodriguez (17-0, 11KOs) and Mexico’s Cristian Gonzalez (15-1, 6KOs) in a scheduled 12-round bout with the vacant WBO flyweight title at stake.

Jake Donovan is a senior writer for Twitter: @JakeNDaBox