Ireland saved two match points before winning a titanic doubles match to lead the Euro Africa Zone Group 11 Davis Cup tie with Estonia in Riverview.
Sam Barry and James McGee looked to be cruising after taking a two set lead against Vladimir Ivanov and Marek Marksoo, 6-4, 6-3.
However, the Estonian duo fought back to level by winning the next two sets 3-6 3-6.
Ivanov and Marksoo had two set points serving at 5-4, but Barry and McGee kept in the game and then broke back, going on to a 9-7 win.
That victory in just under four hours gives Ireland a 2-1 lead ahead of the closing singles games today.