The Cubs' starting pitcher had a shaky outing Sunday, but managed to limit the damage while Lake hit three of Chicago's six home runs and finished with six RBIs in a 10-6 victory over an Oakland Athletics split squad.Hammel gave up eight hits and walked three in 4 2/3 innings. But the A's, who stranded 12 runners, scored two in the first and no more against the Cubs right-hander."This game is a prime example," Hammel said. "Find a way. In games where we're not looking the best, or not at top potential, we can make a run out of something and then we put a five-spot right there."A's starter Jesse Chavez continued his outstanding performance through the first five innings -- a spring that pushed the right-hander into the No. 3 spot in Oakland's rotation as announced by manager Bob Melvin earlier Sunday. Sonny Gray will be the opening day starter.Chavez gave up just two singles and a walk before the Cubs' big sixth. Darwin Barney singled and Chris Coghlan brought him home with a double. Emilio Bonifacio singled with Coghlan holding at third, and Lake followed with his first home run of the spring to put Chicago ahead to stay at 4-2. Luis Valbuena homered on Chavez's very next pitch.Lake's second homer, off Drew Pomeranz, with a man on in the seventh extended the lead to 7-2. Oakland scored three times in its half of the seventh with a pair of errors by third baseman Mike Olt extending the rally. Left fielder Darnell McDonald fell while chasing Tyler Ladendorf's deep fly, and the ball bounced over the wall for a ground-rule double.But in the eighth, Olt homered for the fifth time in the spring to get a run back for the Cubs. Lake and Valbuena connected again in the ninth off Fernando Nieve. Valbuena's second homer gave him six, passing Olt and Javier Baez for the Cubs' spring lead.STARTING TIME:Cubs: Hammel said he was more effective after pitching coach Chris Bosio told him he was working tentatively."Strike one has to be the most important thing for me," Hammel said. "As guys start to know that I'm a sinker-baller, (when) they see it down, they're leaving it down. And I didn't get any balls down."Hammel has one more start before the regular season begins, and he's hoping to get a cleaner outing than Sunday's."It definitely wasn't pretty," he said. "But you grind through it. Obviously you know sometimes you're not going to have your best stuff and you've got to find a way. We did that today."A's: The decision to make Gray the opening day starter was expected after injuries sidelined starters Jarrod Parker (torn ligament in pitching elbow) and A.J. Griffin (elbow ligament strain)."I was excited," Gray said when Melvin told him the news. "I don't think it changes preparation. I knew I was going to pitch at some point. I'm looking forward to a bullpen (session) and my last start of the spring (Wednesday)."Gray has just 10 starts in regular-season play, but he's no stranger to the crowds. He was the ace of the staff at Vanderbilt, and he ended up with a pair of starts against Detroit and Justin Verlander in the American League Division Series last October."He's very quickly become that guy for us," Melvin said. "He's not afraid of the spotlight."Gray's low-key reaction didn't surprise his manager."The poise, the competitiveness, how driven he is," Melvin said of Gray's qualifications. "Whether he's throwing a bullpen, pitching in a game, he's the same guy all the time. He is prepared every single time."Melvin said Sunday that Gray will be followed in Oakland's rotation by Scott Kazmir, Chavez, Dan Straily and Tommy Milone.Gray will be Oakland's ninth opening Day starter in as many years.TRAINER'S ROOMMelvin said pitchers Ryan Cook (shoulder) and Fernando Rodriguez (elbow) and outfielder Craig Gentry (back) will start the season on the disabled list. Melvin said Cook and Gentry, who are active again after sitting out most of the spring, need a little more time."They'll continue to play minor league games," Melvin said. Those won't count against DL time, which began Friday.Cook and Gentry would be eligible to return April 5 during the A's second series of the season, at home against Seattle.A'S MOVESAfter the game, the A's sent pitchers Arnold Leon and Josh Lindblom and first baseman Nate Freiman to Triple-A Sacramento. The moves give the A's 35 players in camp, including two non-roster players -- outfielders Sam Fuld and Billy Burns, both of whom have impressed Melvin.LAST WEEKEND AT MUNIThe A's final Sunday game at Phoenix Municipal Stadium drew a crowd of 6,511. ... The A's, who have home games remaining Tuesday and Wednesday, are leaving after 33 years at the oldest Cactus League facility. They move into the Cubs' former Mesa home, Hohokam Stadium, next season. The A's trained at that Mesa facility from 1969-78.