The Bucs' Williams caught a deep pass for a 30-yard gain to set up the only score by either first-team offense Saturday night, while Miami's Marshall dropped both passes thrown his way in the Dolphins' 10-7 victory.
Williams, a fourth-round draft pick who has already made the starting unit, beat cornerback Vontae Davis along the sideline and caught Josh Freeman's pass for a gain to the Miami 13-yard line. Two plays later, Freeman threw a 13-yard touchdown pass to Sammie Stroughter, who outmaneuvered cornerback Sean Smith to cap a 60-yard drive.
The Bucs' first-team offense played two series, totaling 83 yards in 12 plays with four first downs. Freeman went 4 for 4 for 53 yards, and Carnell Williams carried four times for 21 yards.
Bucs starting receiver Maurice Stovall hurt his ankle in the first quarter and did not return. Tampa Bay rookie cornerback Darrell Pasco left the game with a shoulder injury.
Miami's first-teamers played four series and netted only 39 yards in 15 plays with two first downs. Marshall, acquired from Denver in an offseason trade, dropped a short pass when cornerback E.J. Biggers also got a hand on the ball. Marshall dropped another pass cutting over the middle when wide open.
Miami's Brian Hartline also dropped a pass from Chad Henne, who finished 5 for 11 for 19 yards. Ronnie Brown carried five times for 20 yards, and Ricky Williams ran three times for 10 yards.
It didn't help the Dolphins to run most of their plays in the mud in the first quarter. Heavy rain at the start of the game soaked the dirt infield used for Florida Marlins games.
Bucs backup quarterback Josh Johnson went 8 for 13 for 72 yards and had two turnovers. Against Miami's first-team defense, he ran for 18 yards on a keeper on third-and-16.
Biggers had four tackles and recovered a fumble for the Bucs.
Smith, who had no interceptions as a rookie starter last year, picked off a long pass by Johnson.
Dolphins backup quarterback Tyler Thigpen went 10 for 19 for 145 yards. He directed a drive in the final minute of the first half that ended with a 33-yard field goal by Dan Carpenter, and a 61-yard march capped by Lex Hilliard's 2-yard touchdown run.
Miami's Brandon Fields had punts of 63, 62 and 61 yards, but also had a kick blocked by Corey Lynch.
Tampa Bay had the ball inside the Miami 10 twice in the final minutes but failed to score.