ST. PETERSBURG, Fla. — Tim Wakefield’s first knuckleball floated toward the plate.

Kevin Cash reached out his oversized mitt to catch it, but he wasn’t successful. The ball clanged off his leather and bounced to the backstop.

The third one didn’t settle cleanly into the mitt, either. Nor did the fourth one.

Looking in from third base, Mike Lowell had sympathy for Cash, who has been called up to replace Wakefield’s security blanket behind the plate, Doug Mirabelli. Wakefield’s personal catcher suffered a strained calf last Friday night and is now on the disabled list, necessitating the S.O.S. for Cash.

“It’s a nightmare game of Wiffle ball when Wakefield’s ball is dancing,” said Lowell.

But Cash survived. In fact, he acquitted himself very nicely, settling down after the first two innings, thanks in part to some advice from catcher/captain Jason Varitek and bullpen coach Gary Tuck.

And Wakefield, with an assist from early offense provided by Lowell (two-run double, solo homer) and Manny Ramirez (two-run single), maintained his mastery over the Devil Rays in blanking Tampa Bay for seven innings in Boston’s 6-0 victory at Tropicana Field.

So maybe the Red Sox won’t have to cross their fingers every fifth day with Mirabelli on the shelf.

Cash responded beautifully to the challenge, and the Red Sox got their longest road trip of the season, a 10-game, three-city journey, off to a promising start.

“I thought Cash did a great job,” said Boston manager Terry Francona. “It gives us peace of mind. He wasn’t on pins and needles, so I don’t think we should be. I thought he looked pretty confident trying to accomplish something that’s difficult.

“There were a couple off his glove, but he had a real good demeanor, like ‘I’ll handle this.’ It was kind of contagious with our guys. Sometimes guys band together because of circumstances. Dougie’s not here, and here is a guy in there in a game that is important to us. It (Cash’s success) gives us a boost,” said Francona.

Wakefield, meanwhile, said he had no fears in throwing to Cash. He had caught Wakefield in a side session in spring training and played catch with him after being summoned from the PawSox.

“I thought he did a phenomenal job,” said Wakefield, who was lifted because of a tight back after throwing only 77 pitches in seven innings, allowing four singles.

“I was very comfortable with him back there,” said Wakefield, who had a 5-0 lead to work with after two innings in improving his record to 15-10. “He caught a couple of guys in the minor leagues, in Triple A (Pawtucket’s John Barnes and Charlie Zink).”

Cash, though, said catching Zink and Barnes was hardly the same as catching Wakefield’s butterfly-pitch specialty.

“No offense to them, but it’s no comparison,” said Cash. “I know why (Wakefield) has been so successful for so long. I caught him in the bullpen (warming up last night) and it was fine. But in the game, with hitters up there, it was a different atmosphere.”

For a while, Cash wondered if it was going to be a long night. Akinori Iwamura, the Devil Rays’ leadoff man, drew a six-pitch walk — two fastballs and four knucklers, one of which Cash caught cleanly. Iwamura stole second when Cash couldn’t yank a knuckler out of his mitt to make a throw, and went to third when Cash mishandled a swinging strike three against Carl Crawford and had to throw him out at first.

That passed ball put Iwamura at third with one out.

But Cash didn’t mishandle another one in the inning, helping to strand Iwamura.

“I shook it off,” said Cash of the first-inning knucklers off the mitt. “The guy didn’t score from third. I came in (to the dugout) and cracked a few jokes. I figured if (the balls got away) I’d just go back and get them. I tried not to let it get to me.”

He had a few bounce off his mitt in the second, but after that settled in nicely and the Rays helped out by swinging early in the count, making very quick and soft outs.

Varitek and Tuck, who called in from the bullpen with a little advice, deserved a major assist.

“They said that Dougie shifts out and angles his body (in receiving the ball). Once I did that I felt more comfortable. And Wake did a good job of keeping them off the bases,” said Cash.

Cash, though, was able to gun down B.J. Upton trying to swipe second in the sixth inning, no easy feat considering a catcher has to first let the knuckler flutter to him.

“I think that was a big moment for him,” said Lowell. “It’s going to be an adjustment period for him. I wouldn’t want his job for anything.”

skrasner@projo.com