Kevin Kiermaier looked to have given the Tampa Bay Rays a lead in the top of the 13th inning of Sunday night's thriller at Fenway Park with a double to right field, plating Yandy Diaz for a 5-4 lead over the Boston Red Sox.

Trouble was, Kiermaier's double took a most unfortunate bounce for the Rays -- much to the delight of the Red Sox, who'd go on to win the game in the bottom of the 13th on Christian Vazquez's walk-off homer.

Kiermaier's ball struck off the base of the short wall in right field at Fenway and proceeded to spin back towards Red Sox right fielder Hunter Renfroe, who was unable to make a play on the ball as it bounced over the fence.

The call on the field was a ground-rule double, keeping Kiermaier at second base and forcing Diaz, who had been on first base, to hold at third rather than score what would have been the go-ahead run.

Both Kiermaier and Diaz, who was already around second when the ball landed over the fence, were stranded when Nick Pivetta struck out Rays catcher Mike Zunino to end the inning and set the stage for Vazquez's heroics.

Here's the rule which allowed the Red Sox to remain tied with Tampa headed into the bottom of the 13th: