Matt Chapman capped a five-run sixth inning with a grand slam and the San Francisco bullpen threw four innings of shutout relief as the Giants overcame the visiting Colorado Rockies 6-3 on Saturday afternoon.After the Rockies had scored three times in the top of the sixth to go up 3-1, Colorado starter Bradley Blalock issued walks to Luis Matos and Mike Yastrzemski to set the stage for San Francisco’s comeback.Reliever Jake Bird (0-1) took over at that point and walked Willy Adames to load the bases. Jung Hoo Lee singled to center to drive in Matos and draw the hosts within 3-2.Two pitches later, Chapman teed off on Bird for a 402-foot bomb to center field — clearing the bases and putting San Francisco in front, 6-3.The grand slam was the third of Chapman’s career, all of which have come since April 2023. It was his seventh homer of the season.Three of the inning’s five runs were charged to Bird. Blalock also was charged with three runs over his 5 1/3 innings, during which he allowed just two hits. He walked two and struck out four.Giants relievers Camilo Doval, Erik Miller and Ryan Walker retained the three-run margin to the end with an inning apiece of hitless ball. Randy Rodriguez (2-0), the pitcher of record at the time of the five-run uprising, was credited with the win while Walker notched his sixth save.San Francisco starter Jordan Hicks took a shutout and 1-0 lead into the sixth before walking Brenton Doyle and serving up singles to Jordan Beck and Ryan McMahon — the latter tying the score.