By Caroline Cheese
BBC Sport at Wimbledon
World number two Rafael Nadal had been taken to a fifth set by big-hitting Swede Robin Soderling when rain brought play to an end on Monday.
Nadal had a match point in the third set but went narrowly wide
The second seed was leading 6-4 6-4 and had already squandered a match point in the third-set tiebreak when rain forced the players off earlier in the day.
But when the tiebreak resumed at 7-7, Soderling won the next two points and then clinched the fourth set.
Nadal will take a 6-4 6-4 6-7 4-6 2-0 lead into Tuesday's play.
If he prevails, last year's finalist will face Mikhail Youzhny in the fourth round after the Russian overcame Jarkko Nieminen 7-5 7-6 6-3 on Monday.
The delay to the match leaves Nadal with the prospect of having to play five days in a row if he is to reach the final for the second year running.
He was agonisingly close to wrapping up victory over Soderling in the third-set tiebreak, going narrowly wide with a backhand.
And when the players returned, Soderling appeared the more focused, with Nadal apparently unhappy at having to play in the gloomy conditions.
There was a flashpoint at the start of the fifth set when Soderling delayed Nadal's serve by going to get a new racket, prompting the Spaniard to use some delaying tactics of his own.
Soderling responded by copying Nadal's habit of picking at his shorts - but the incident only seemed to fire up Nadal and the Spaniard broke before the rain returned.
On another frustrating day for spectators at Wimbledon, Marcos Baghdatis beat the showers to complete a surprisingly easy victory over David Nalbandian.
Baghdatis reached the semi-finals at Wimbledon last year
Last year's semi-finalist triumphed 6-2 7-5 6-0 in one hour 41 minutes in between Monday's rain delays.
"I wasn't expecting that," said Baghdatis. "He didn't play very well, but I'm happy the way I'm playing."
Baghdatis, seeded 10th, will face the winner of the encounter between Gael Monfils and Nikolay Davydenko.
Sixth seed Davydenko is leading that match 6-3 7-5 3-0.
Tomas Berdych dodged the showers to wrap up a third-round win over South Korean Hyung-Taik Lee.
The Czech seventh seed had established a 6-4 2-3 lead on Saturday and ran out a 6-4 7-6 7-6 winner when play resumed.
Berdych will meet Jonas Bjorkman, who was an easy winner over Wayne Arthurs 6-2 6-1 6-4.
It was the last singles match for 36-year-old Arthurs, who is retiring after this tournament.
Lleyton Hewitt and Guillermo Canas will return on Tuesday with their match poised at one set all, with Hewitt leading the third set 3-1.
The winner of that match will face Novak Djokovic or Nicolas Kiefer. Djokovic took the first set on Monday and was leading 6-5 when play was suspended for the day at 2030 BST.