OMAHA, Neb. — Carson Fulmer combined with two relievers on a four-hitter, Will Toffey’s two-run double broke a scoreless tie in the sixth, and defending national champion Vanderbilt opened the College World Series finals with a 5-1 victory over Virginia on Monday night. The Commodores (51-19) need one more win, Tuesday or Wednesday, to become the seventh team to win back-to-back national titles, and the third to do it in the last 10 years. Fulmer (14-2) struck out eight, walked two and hit two batters in his 20th consecutive start of at least five innings.