SAN DIEGO — Tony Vitello had trouble sleeping at times in February and March, but not because of all that was on his plate as Giants manager. The dry air in Scottsdale was not exactly kind to his allergies. Vitello probably didn’t sleep very well when the Giants returned home last week. By all accounts, he was more invested than most managers would be as the Giants sent players back to Triple-A and cut down their roster. Once the games started, Vitello’s team got overwhelmed for three days.On Monday night, Vitello shouldn’t have any trouble when his head hits the pillow. The Giants finally won a game, scoring three early runs and riding a dominant pitching performance from Landen Roupp, who had plenty of reasons to savor this night. The 3-2 win over the San Diego Padres kept them from losing their first four games of a season for the first time since moving to San Francisco. Harrison Bader got it going with a solo homer in the third, the first of the year for the Giants, who scored just one total run in their first three games. After a two-run explosion in the second, Roupp seamlessly carried the baton to the rebuilt bullpen, which has been a...