Spaniard Nadal, who also saw off Soderling's challenge in the French Open final earlier this month, squandered his first match point before sealing victory with a trademark rasping forehand down the line.
The former champion, who missed last year's Wimbledon with knee problems, will face either Britain's Andy Murray or Frenchman Jo-Wilfried Tsonga in the semis.
"I started so, so but Soderling was playing very long and powerful," second seed Nadal told reporters.
"I had some problems at the start of the second set with the break point, I play it well and after that I think the match changed a lot," he added.
After six-times champion and top seed Roger Federer suffered a shock defeat to Czech Tomas Berdych, Nadal will now be favourite to take the title -- even if he did not say so himself.
"Roger did amazing the seven years, he was unbelievable. One day you have to lose and Berdych is a very difficult opponent... I just wish the best for Roger for the rest of the season," Rafa said.
"But in my opinion there is no one favourite for the tournament," he added.
Soderling's first Wimbledon quarter-final started at blistering pace as he raced into a 5-0 lead before seeing off a mini-Nadal revival to take it 6-3.
Seven-times grand slam winner Nadal had struggled on serve and looked unusually sluggish against the Swede's powerful groundstrokes in front of a fairly subdued Court One crowd.
The Spaniard needed a boost and received in the first game of the second set. Angered by a Hawk-Eye call that put Soderling at break point, Nadal set about improving his play before sealing the game and the next two.
The hard-hitting pair settled into a rhythm of solid rallies but it was Nadal who looked the sharper as a tense Soderling attempted to force winners without avail, handing the left-hander the second.
Sixth-seeded Soderling called for the trainer when trailing 4-5 in the third and the treatment on his left foot for a blister almost worked wonders as he broke back and went 6-5 ahead only to lose the tie-break 7-4 after watching the ball hit the tape and drop dead.
Nadal smelt victory and broke to go 3-1 up in the fourth before racing to a comfortable 6-1 win and a place in the semi-finals.Nadal batters Soderling for 5th French Open crown
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