The Warriors are the in-form team in the RaboDirect PRO12, winning their last seven games on the spin, including Friday's 38-16 triumph over Treviso.
It keeps them second in the table, with just a home game against Zebre remaining of the normal season before the play-offs begin.
Zebre themselves also won last time out, defeating Ospreys 30-27 although Townsend believes the momentum is well and truly with his side.
"The players have worked really hard for these seven wins," said Townsend. "We've used something like 35 players in this period and those coming in last night did really well.
"There is good competition for places. You've got to change the team if you want to be fit and fresh and dynamic at the end of the season.
"We've built really good momentum and got ourselves in a wonderful position. A win gets us a home semi-final and that would be fantastic for rugby in the west of Scotland.
"But Zebre have shown they are a much-improved side recently - they have beaten Ospreys and Edinburgh - and we'll need to prepare well."
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Guinness PRO12
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The Sweepstakes
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