SAN FRANCISCO -- The San Francisco Giants should win the National League West this season, in large part because they have the kind of starting pitching that makes major accomplishments possible, maybe even probable.

The overall quality of their starting pitching continues to look better than of that of their primary rival and main divisional opponent, the Los Angeles Dodgers. This is particularly the case with the Dodgers' No. 2 starter, Chad Billingsley, out for the season with a significant elbow injury.

Part of this calculation rests on the considerable worth displayed by Tim Lincecum over the course of his career, including most notably being dominant enough to win consecutive National League Cy Young Awards. But this season, Lincecum, who once routinely baffled hitters, has also at times confounded the Giants

Friday night, in the opener of a crucial series with the Dodgers, Lincecum was occasionally brilliant, often erratic with his command, but overall, good enough. He made pitches when pitches had to be made. There may have been as much of the enigmatic as the great in this performance, but at the end the Giants had a 5-2 victory and a 5 1/2-game lead over the Dodgers.

Lincecum and the Giants had eliminated the one possibility that could have damaged them seriously -- a sweep by the Dodgers. Now, at worst, the Giants will leave this series with a 3 1/2-game lead. Their existing edge in the standings gave the Giants a much more positive perspective going into this series.

"Obviously, it's a lot more important for us than it is for them," Dodgers manager Don Mattingly said.

Lincecum, meanwhile, had a strange statistical journey through 6 1/3 innings. He struck out seven and allowed only two runs on four hits. But he walked a career-high seven; one in each of the innings he pitched. Still, there were only the two runs allowed, and when he departed in the seventh, with a pitch count of 119, he left a tie game.

On Lincecum's side of the argument, the second half of this season much more closely resembles the rest of his career than the first half. The first half (3-10, 6.42 ERA in 18 starts) appeared to be entirely somebody else. In the second half, he is 5-4, with a 3.22 ERA in 11 starts.

Lincecum is no longer regularly throwing fastballs at speeds above 95 mph. He was in the low 90s Friday night, at 91 with considerable consistency. But the drop in velocity shouldn't automatically preclude a pitcher of his ability from being successful. Based on his recent work, he is making successful adjustments. He made mechanical adjustments on the fly Friday night, persistently coming back from the walks to regain his command.

"It all starts with the starter, and he just did a terrific job for us tonight," Giants manager Bruce Bochy said of Lincecum. "Just great composure and poise out there. He had good stuff and all his pitches were working. He could throw any pitch at any time. He mixed in a few walks, but he adjusted out there and made the pitches when he had to. And that's what he's so good at. They had some runners on base, but he kept his focus and made great pitches when he had to.

"I thought he was pretty good tonight, although he did mix in some walks. But he wasn't missing [by] much. You hate to see the walks, his pitch count got up there, but he just had a good look about him. Even though he was walking guys there was no panic in him. He kept his poise out there and kept pitching."

Lincecum said that his slider was his "go-to" pitch in this game. He indicated that he had been able to figure out the mechanical issues that occurred during some of the walks and move on from there. The walks bothered him to the extent that they forced him into an earlier exit than he would have liked.

"If I could have eliminated even a couple of walks," Lincecum said, "that's 15 more pitches I could have put toward getting guys out."

But at the end of the day, the walks Lincecum issued were more of a curiosity than a concern. His overall performance had contributed to a Giants victory in what could be considered a pivotal game. This is not the same as winning two Cy Young Awards by the age of 25. But when the Giants needed him to come through with a big performance against, of course, the Dodgers, Tim Lincecum was once again more than good enough.