Westwood birdied the 18th for a 69 to tie Poulter (68) for the outright lead over the Barseback Golf Club at 13-under-par 203.
The duo heads an impressive list of European talent, including Colin Montgomerie (69) and Peter Hedblom (68), who are a shot back at 12-under.
One shot further adrift at 11-under is 1999 Open champion Paul Lawrie, while three others are three back including Northern Irelands Darren Clarke, who shot 70 on Saturday.
The developing story seems to be centering around Sundays final pairing.
While Westwood is looking to redeem himself as one of the tours best, Poulter is attempting to establish himself with a punch of certainty.
In just his second season on tour, Poulter is gunning for his third win. The 25-year-old took the 00 Italian Open on his way to being named Rookie of the Year, and has already championed at this years Moroccan Open.
The youngster made an impressive move on Saturday, birdieing the 17th and nearly holing his approach to No. 18, before finally settling for par after a missed birdie attempt.
Meanwhile, Westwood ' the seven-time worldwide winner and Order of Merit champion in 2000 ' is in the midst of a terrible season, missing four cuts and only recording two top-10s in 11 events this year.
He is making amends for the lost time this weekend, however, as he erased a lone bogey at No. 13 with four red numbers, including the clincher at the last.
The man Westwood replaced as the leading money winner is on a bit of a comeback himself.
Montgomerie over the last 12 months has been visibly lacking of the form which led him to seven consecutive money titles, but he seems to be getting his game back on track in recent times.
A strong showing at the 130th Open Championship and a win at the Murphy's Irish Open have gotten him to No. 8 on the Ryder Cup points list, and he is a good bet to compete at the Belfry.
Clarke, too, will be in this years Ryder Cup ' that is a certainty.
Nearly 400 points higher than the rest, he has a lock on this years edition, and will improve his standings even more with a high finish this weekend.
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