Ragged Roddick struggles in summer grass opener
Roddick's first match of the season on grass was marked by early struggle as the world number 127 Dancevic, playing his fifth match on the surface since last weekend, broke twice to claim the opening set.
It took all of third seed Roddick's pool of experience to finally put things right, emerging with a narrow win into the third round after missing on nine break point chances in the one-hour, 25-minute contest.
"I struggled a little bit early, I wasn't totally comfortable," said the American.
"As the match went on, I played better and better and better. I was starting to find my range."
Victory lifted Roddick, without a title since last October and not even a final to show for in 2006, to an impressive 16-1 mark at Queen's, the top Wimbledon tuneup.
Roddick, hammered in the last two Wimbledon finals by Roger Federer, was playing his first grass match since playing in his country's Davis Cup victory over Chile in April.
"I didn't return first serves very well early on, I don't know if I made him play much," said Roddick. "That led to him being a little bit more free with his swings."
Dancevic, who has played mainly on the lower-level Challenger circuit, was not intimidated by the reputation of the former world number 1, converting on two of his three break points.
After a partial rain-out on Tuesday, the day's program was crammed with 20 matches at the west London club.
Home fans were served up a distasteful defeat around lunchtime on the lawns as British tyro Andy Murray crashed out to Serb Janko Tipsarevic 7-6 (7-3) 3-6 6-2 in a match interrupted with Murray leading 5-2 in the second set on Tuesday.
A year ago, the 19-year-old Scot made his big-match breakthrough here.
But without a coach for two months, Murray has won only two recent matches and failed to thrill the local public on a grey day.
In his continuing campaign to damp down any Wimbledon enthusiasm, Murray said that he will always find it tough on grass.
"Before last year I hadn't played too many matches on grass. I trained in Spain until I was 16, I hadn't even hit on a grass court before. "I don't expect it to be my best surface. It's a surface which will take some time getting used to and finding the right way to play on it."
Australian Mark Philippoussis earned a welcome win as he put out South African Wesley Moodie 6-3 6-4 to reach the second round.
The 2003 Wimbledon finalist, the 1997 Queen's winner, whose ranking now stands a lowly 176, was playing in only his fifth match since early April.
Second seed Ivan Ljubicic got off to a comfortable start after his transition to grass as he defeated Romanian Razvan Sabau 7-6 (8/6) 6-2.
Thai number 16 Paradorn Srichaphan won his second match on grass this week, defeating Yeu-Tzuoo Lu of Taiwan 6-3 5-7 6-4.
French Open champion Rafael Nadal, who watched Spain's World Cup match in the hours before his opening contest, was facing American Mardy Fish in the second round.