"It's kind of like driving into head-on traffic," Roddick said.
Though counterintuitive, the tactic worked, and Roddick rallied for a 4-6, 6-3, 6-3 victory Friday in the Sony Ericsson Open semifinals.
Once Roddick fell behind, he became more aggressive, even following his second serve to the net on occasion. Momentum turned when he won the last 11 points of the second set, including a 143-mph serve -- the fastest by any player in the tournament -- for a winner on the final point to even the match.
Roddick kept coming, winning 12 points at the net in the final set. He also put more oomph into his forehand, especially on returns.
"I took a lot of risks there in the last two sets," he said. "I rolled the dice a lot and came up Yahtzee a couple times."
To the delight of traditionalists, Roddick played serve and volley 10 times. Rumors are he'll use a wood racket in the final Sunday against 16th-seeded Tomas Berdych, who advanced by beating Robin Soderling 6-2, 6-2.
Berdych upset top-ranked Roger Federer in the fourth round. The Czech's only other Masters 1000 final was in 2005, when he won the Paris title.
"You feel well on the court and build your confidence -- that's what's happening," Berdych said. "It's small things put together, and that makes a pretty good game for me."
The No. 6-seeded Roddick reached the Key Biscayne final for the first time since winning the championship in 2004. He's seeking his first Masters 1000 title since August 2006 in Cincinnati.
Roddick vs. Nadal felt like a final. The near-capacity crowd included Tiger Woods' wife, Elin, and their son Charlie, who watched under an awning at the skybox level near the players' lounge.
South Florida's polyglot population made for divided fan support, with chants of "An-dy!" and "Ra-fa!" drowning each other out.
"Vamos, Andy!" one fan shouted.
Like his pal Dwyane Wade, Roddick won going to the net.
"He started to play more aggressive," Nadal said. "It was a surprise for me."
In the final set, Roddick took the lead for good when he broke in the third game. He won a key point playing serve and volley in the tense eighth game, held for 5-3 and broke again for the victory.
Roddick won every set in his first four rounds by playing error-free tennis from the baseline and relying on his big serve. He tried that approach against the No. 4-seeded Nadal, but it wasn't enough.
Nadal won 49 baseline points to 29 for Roddick. Almost every extended exchange went the Spaniard's way.
"It was like water torture," Roddick said. "My comfort zone of moving the ball around and maybe chipping it around a little bit doesn't work against Rafa. It's very tough once we get neutral. I don't hit the ball like him."
So Roddick decided to gamble. His first forehand winner came 18 games into the match -- and gave him a service break for a 5-3 lead.
"I literally took really, really ridiculous cuts at a lot of forehands," he said.
With the surge at the end of the second set, Roddick snapped a steak of seven consecutive sets he had lost to Nadal over the past two years. The tide had turned.
When Nadal sailed a forehand long on the final point, Roddick hunched over as though stunned.
"I was like, 'I can't believe he actually just missed a ball on his forehand,'" Roddick said. He then walked slowly to the net, where Nadal waited with a handshake.
Nadal had four break-point chances but converted only once. Roddick has saved 12 of 14 break points in the tournament, and over the past six matches he has held in 62 of 64 service games.
Despite 15 aces and 39 unreturned serves against Nadal, Roddick said his big serving wasn't the difference.
"Don't get me wrong, I enjoy it," he said. "But I don't think that's the thing that won it for me today."
Nadal remains without a title since winning at Rome last May. At Indian Wells last month he also lost in the semifinals.
"If you are there, you're going to win one day," Nadal said. "I am happy how I am doing."