PHOENIX -- A's center fielder Yoenis Cespedes made the most of his first official Major League game on Saturday, lining a homer to left to lead off the fourth inning and drilling a ground-ball RBI single to center with runners on first and third and one out in the second.

The homer came off the sixth pitch from Reds left-hander Jeff Francis, who had just entered the game. Cespedes fouled off four consecutive pitches before lining the ball toward Van Buren Street.

"I love the way he came up," A's second baseman Jemile Weeks said. "'Bam, this is what I do.'"

The A's won the game, 6-3.

Cespedes came out swinging in his second at-bat against starter Johnny Cueto, tapping a grounder foul down the third-base line on the first pitch and then smacking a single on the next one. That followed a six-pitch full-count walk in the first inning in which Cespedes didn't offer at a pitch.

"They were all impressive," A's manager Bob Melvin said about the Cespedes at-bats. "But his first at-bat was as impressive as the others, because you know he wanted to go up and show what he has, and he took a walk."

Cespedes' final line was 2-for-2 with a homer and two RBIs in four innings, making two catches in center field where Melvin said he also looked very comfortable. Melvin added that Cespedes will be the designated hitter vs. the Royals on Sunday when the A's play again at Phoenix Municipal Stadium at 1:05 p.m. PT, batting in the third or fourth spot in the lineup.

For his part, Cespedes said he felt the pressure, but he rose to the occasion.

"Things will get better," Cespedes said through Ariel Prieto, the Cuban-born pitcher who also played for the A's and is acting as his liaison and interpreter. "I just had three at-bats today. The pitching is much different here than it is in Cuba. I have to play more and adjust. This was the first game. I felt a little pressure on me today when I went to the plate."

The much-awaited Cactus League debut of the Cuban-born right-handed swinger was played before a raucous crowd of 6,644 on a beautiful sun-splashed day in the desert. The A's dugout was packed with players who weren't even slated to play on Saturday, Melvin said -- all there to watch Cespedes do his thing. To his point, Weeks was not in the lineup, but was still around late in the game when reporters interviewed Cespedes.

Melvin joked to reporters with a big smile on his face in the clubhouse earlier that this was a special day.

"There's nothing to see here today. Nothing to see here today," he said.

Later, Melvin said that the buzz around Cespedes' debut was definitely good for the franchise.

"This is a day we've had marked on the calendar," Melvin said. "With limited resources, this is similar to what Cincinnati did [a couple of years ago] with [Cuban pitcher Aroldis] Chapman. We have potentially a chance to get a very high-end player. We don't have many opportunities to do that." 

Cespedes had to work his way through a week of obstacles to get here. The decision was made for him to play on Saturday after Cespedes played in his third consecutive simulated game at Papago Park, the A's nearby training complex, on Friday. In one of the most highly attended simulated games, Cespedes went 1-for-4 with an infield single and a strikeout, and played center.

The entire A's hierarchy was there from owner Lew Wolff and general manager Billy Beane on down to Melvin, who was present for a few innings before catching the bus to nearby Scottsdale, Ariz., for a Cactus League game his team won, 6-4, over the Rockies. Beane had said afterward that a green light from the training staff was the only impediment to Cespedes playing. That green light obviously was given.

Cespedes was evidently game ready. In the previous two simulated games, he hit two homers -- one in each game -- and went 3-for-6 on Thursday.

Even the Reds arrived at the ballpark with great anticipation.

"I talked to a couple of Cuban friends I have in Miami, and they told me he was a pretty good ballplayer," Reds manager Dusty Baker said. "I'm surprised the A's signed him."

The A's indeed signed Cespedes this month to a four-year, $36 million contract, their highest impact acquisition of the offseason.

Cespedes is only 26 and has a chiseled body. His upside potential is obviously tremendous. He began playing for the Cuban national team in 2003 and many may remember him tearing the hide off the ball in the '09 World Baseball Classic when he hit .458 with one double, three triples, two home runs, five runs and five RBIs in six games, even though the Cubans were eliminated by eventual title-winning Japan in the second round.

That is all behind him, though, now and the yard stick for Cespedes is succeeding in the Majors.

"I am going to try to be a better player here than I was in Cuba," he said. "This is the best baseball in the world. There's not even any comparison."