SAN FRANCISCO -- Brian Dallimore's 10th-inning single to right off Tim Harikkala scored Angel Chavez with the winning run, giving the San Francisco Giants a 4-3 victory over the Oakland A's on Friday night at SBC Park.
The winning pitcher was Jeremy Fikac (1-0), while Harikkala's record fell to 0-2.
Giants rookie Lance Niekro slammed a two-run homer, his second of the spring.
Niekro's homer came off Juan Cruz in the seventh inning, giving San Francisco a short-lived 3-2 lead. Yorvit Torrealba had led off the inning with a triple.
In the A's eighth, Jermaine Clark doubled off Scott Eyre, with pinch-hitter Scott Hatteberg driving Clark home with the game-tying score.
San Francisco starter Brett Tomko allowed only one run on three hits over five frames while striking out five. Oakland counterpart Kirk Saarloos threw five shutout frames.
Oakland scored in the second inning when Mark Ellis was safe on a fielder's choice and later scored when Saarloos punched an RBI single through the left side of a drawn-in infield.
J.T. Snow led off the sixth with a bloop single to left against Cruz, then pinch-runner Adam Shabala came home on an infield out by Edgardo Alfonzo.
Oakland took a 2-1 lead in the seventh when Marco Scutaro drove in Eric Byrnes with a base hit off reliever Scott Munter.
Rich Draper is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.