SAN DIEGO -- — Harrison Bader connected against Walker Buehler for San Francisco's first home run this season and the Giants held off a late rally by the San Diego Padres to give rookie manager Tony Vitello his first victory, 3-2 on Monday night. Ryan Walker was one strike from closing a two-hit shutout when he allowed a two-run homer to Jackson Merrill. Walker then got Xander Bogaerts to ground out to finish the combined three-hitter for a save. Vitello, hired from the University of Tennessee despite no professional playing or coaching experience, and the Giants had a miserable opening series. They were outscored 13-1 by the New York Yankees in a three-game sweep, becoming the 11th team to score no more than one run over the initial three games of a season. They matched a franchise record Saturday by reaching 20 innings without scoring to begin the season before finally getting a run in the third inning of a 3-1 loss. The Giants were also the only team without a home run this year until Bader drove a 1-2 pitch from Buehler (0-1) off the facade of the second deck in left field leading off the third. San Francisco added on with consecutive RBI singles with two outs in the fourth by Patrick Bailey and Casey Schmitt, who played at suburban Eastlake High and San Diego State. Landen Roupp (1-0) allowed two singles while striking out seven and walking two in six innings. The 31-year-old Buehler, who pitched for the Los Angeles Dodgers his first seven seasons, is back in the NL West after pitching for Boston and Philadelphia last season. He was a spring signee and earned a spot in a rotation minus Yu Darvish for the season following elbow surgery and Joe Musgrove, who began the season on the injured list with right elbow inflammation after his own return from Tommy John surgery went slower than hoped. Buehler allowed three runs and five hits over four innings in his Padres debut. Up next Giants RHP Logan Webb (0-1, 10.80 ERA) and Padres RHP Germán Márquez are scheduled to start Tuesday night. It will be Márquez's debut with San Diego. ------ AP MLB: https://apnews.com/hub/MLB