|Federer will be gunning for a fifth Dubai Open title in Saturday's final [EPA]
Roger Federer beat Juan Martin del Potro 7-6 (7/5), 7-6 (8/6) to reach the final of the Dubai Open on Friday with the Swiss great saving four set points in the second set tie-break.
Federer will meet Briton’s Andy Murray, who earlier defeated world number one Novak Djokovic 6-2, 7-5.
Saturday's match will be Federer's 102nd career final where he will also get the chance of extending his record of Dubai Open titles to five at his second home.
Federer scored his third win this year over the dangerous Del Potro, who returned to the world's top 10 last month for the first time since wrist surgery in 2010 consigned him to a ranking close to 500.
But it required Federer to make a fine comeback in the second set tie-break, in which he was 2-6 down with four set points against him before producing a wonderful six-point streak to close the match out.
"I hung in there and I thought I played a good match," said Federer.
"He almost pulled the first set 'breaker back from 2-6, and there was little between us tonight. I just fought well and got a little lucky.
"It's good to see Juan back and it's good to be in another final. It's also nice to play again against Andy as I don't think we played at all last year."
The first set Friday was a tussle between Federer's fluid movement and easy evolution between defence and attack, and the fierce flat-hitting and serving of Del Potro.
It hinged on the tie-break in which Del Potro made two forehand driving errors on his service points, while Federer lost only one service point, with an over-hit backhand drive.
It would have been easier had Federer converted two set points in the eleventh game.
But Del Potro played those points well and similarly served and hit his way out of trouble three times at break point down in the third game of the second set and once in the fifth game.
That caused the match to go to another tie-break. When del Potro led six points to two he seemed to have established a hitting rhythm from near the baseline which might be a winning formula.
But Federer contained and defended brilliantly on rallies behind Del Potro's serve at 6/2, 6/5 and 6/6, eliciting forced errors which turned the match back his way.