ST. PETERSBURG -- It was one of the highlights of the previous season for the Blue Jays: Gregg Zaun, sprinting around the bases in Toronto, smiling wide and wildly celebrating a walk-off grand slam delivered against the Rays in extra innings late in the year.

On Sunday afternoon, Zaun -- now with Tampa Bay -- turned the tables on Toronto, launching another home run with the bases loaded, sending his former club to a 5-2 loss at Tropicana Field. Long before Zaun stepped into the batter's box in the eighth inning, though, the Jays had ample opportunities to swing the contest in their favor.

Toronto stranded 10 baserunners, squandering many opportune situations and wasting a fine six-inning effort from rookie starter Marc Rzepczynski. The result was the ninth loss for the Jays in 12 games against Tampa Bay this season, including five defeats in six tilts against the Rays on the road.

"We had a lot of opportunities," Blue Jays manager Cito Gaston said. "A base hit or a fly ball and it's a different ballgame. That's too bad. Zep pitched pretty good for us and gave us a chance to win, but we certainly didn't take advantage of the opportunity to win."

In the eighth inning, Gaston turned to Brandon League with the Blue Jays (55-61) and Rays locked in a 1-1 tie. With one out, League allowed a single to Ben Zobrist and a double to Carlos Pena before intentionally walking Willy Aybar to load the bases. Tampa Bay turned to left-handed-hitting Gabe Gross as a pinch-hitter.

League slipped to a 3-2 count against Gross and eventually used a hard splitter to strike him out. The Rays (63-54) then turned to Zaun as a pinch hitter and the veteran catcher -- after spending the past five seasons as a member of the Blue Jays -- watched the first four pitches to work to a 3-1 count against League.

After swinging and fouling off a 94-mph fastball, Zaun knew there was a chance that League might turn to his splitter again in a full count -- not just due to the sequence of pitches to Gross one at-bat earlier.

"I had that in the back of my mind based on the last at-bat that I had against him in Toronto," said Zaun, who was acquired by the Rays in a trade with the Orioles on Aug. 7. "He got ahead of me with a fastball and then he just absolutely abused me with two splits. I knew I was going to see at least one at some point in that at-bat.

"He's been throwing it so great this year -- he's really turned a corner with that pitch. Before, when I was there, one out of every six or seven was usable. Now, he's throwing it around the plate all the time."

League opted to stick with his fastball, and it cost him in a big way.

"I think everyone in the whole stadium knew what I was going to throw," League said. "I just left it in the middle of the zone and he did what he did with it. ... I just kind of went with my gut feeling."

Zaun yanked the offering from League to right field, where it carried over the wall for the catcher's fifth career grand slam. It marked the sixth career pinch-hit blast for Zaun and his first grand slam since Sept. 6 of the previous season. In that game, Zaun cleared the bases with a 13th-inning shot against the Rays that lifted the Jays to a 7-4 win.

At the time, Zaun said that game-winning home run was one of the highlights of his career. On Sunday, he said the latest grand slam isn't far behind.

"There's really no substitute for the enthusiasm that you feel for an actual walk-off," Zaun said. "But ... for me to be able to come in and get a big hit and contribute to a team that's got a chance to be playing in October, I'm sure in an hour or two when I get a chance to sit down and be quiet, it'll sink in a little bit more.

"Initially, obviously the walk-offs are a little bit more exciting, but this one ranks up there for me."

In the third inning, the Blue Jays used three consecutive singles from Joe Inglett, Marco Scutaro and Aaron Hill to load the bases with no outs. There would be no grand slam for Toronto, though -- only another missed opportunity. Rays right-hander Matt Garza, who was chased after using 103 pitches in five innings, retired the next three hitters to escape the jam.

Toronto's lone run against Garza came in the fifth inning, when Hill singled to left field and scored on a base hit to center by Vernon Wells. On the play, Tampa Bay center fielder B.J. Upton made a strong throw home, where Hill collided hard with catcher Dioner Navarro. Hill pushed Navarro down, avoiding a tag, and touched the plate with his fingertips.

In the ninth, Scutaro added a solo home run. By that time, though, Zaun's eighth-inning swing had caused too much damage to overcome.

That fact that it was Zaun who delivered the game's decisive blow mattered little to League.

"It could've been anyone on that team," League said. "It still feels the same. A loss is a loss."