The Central baseball team used strong defense and dominating pitching  allowing just four runs on the weekend on their way to a three-game Iowa Conference road sweep, overpowering Dubuque 7-2 and 12-1 Saturday after posting a 6-1 victory Friday.    It’s the first time the Dutch  have swept a three-game series on the road since the conference added them to the schedule in 2007.   <Caleb Rangel pitched four more innings Saturday after throwing the first frame Friday before the game was suspended because of rain. He allowed five hits in five innings and improved to 3-1. Doug Eisenman followed with two hitless innings to close. Central outhit Dubuque 9-5.  D.J. Glasgow allowed just one run in eight innings in the final game of the series, scattering nine hits while walking one and fanning five.    Meanwhile the Dutch defense committed just one error on the day and turned four double plays.   Central had 12 hits in the second game and took advantage of eight Dubuque errors.  Third baseman Anthony Miller had a big day, scoring five runs and driving in three while getting three hits. Shortstop Mike Furlong had four hits and center fielder Ryan Allison had three hits and scored four runs.  The Dutch improved to 13-6 and 4-2 in Iowa Conference play and will  play its final non-conference doubleheader Monday, playing host to Martin Luther at 2 p.m. at the A.N. Kuyper Athletics Complex field.  Then the Dutch play a single game at Coe Wednesday, before a three-game series at Cornell Friday and Saturday.