The South African was a hero at Goodison Park in his first spell, making more than 100 appearances between July 2007 and January 2011, when he joined Tottenham.
But he found chances hard to come by at White Hart Lane this season and made his first Barclays Premier League start of the campaign on Saturday after rejoining the Toffees on loan on Tuesday.
Moyes said: "I thought Steven Pienaar was the best player. He looked as if he hadn't been away, he was involved in a lot of bits where we looked as if we were on the verge of making things happen.
"They tended to break down round the box or we didn't get the vital shot away but Steven Pienaar played really well."
Moyes' other deadline-day signing, striker Nikica Jelavic, also made his debut, coming off the bench in the second half, and his manager is keen to give the former Rangers player time to adapt.
"He did fine," said the Toffees boss. "He's only just come in so it's difficult to judge. He only really joined us on Friday so we'll give him a chance to settle in and be part of it."
Everton, who lost Tim Cahill to foot and calf problems at half-time, did not reach the heights that saw them beat Barclays Premier League leaders Manchester City on Tuesday but Moyes felt they deserved the point given to them by Victor Anichebe seven minutes from time after Phil Neville's bizarre own goal.
"It was a crucial goal for us," said Moyes. "I didn't think we deserved to be in such a position but great credit to the lads for coming back.
"I've seen Wigan a few times and they're playing better than their scores are suggesting or where they are. They played well against Arsenal and Manchester City here so it was never going to be an easy game."
The draw put an end to Wigan's five-match losing run but left them still five points adrift of safety with 14 games remaining, a scenario manager Roberto Martinez felt got the better of his players in defeats by QPR and Tottenham.
The Spaniard said: "I wasn't happy with the last two performances, I thought the situation we are in in the table really affected us but that wasn't the case (yesterday).
"I saw a free team, a group of players who really enjoyed getting on the ball and working for each other and that really pleases me and gives me great confidence to look forward to the end of the season.
"We've been in this situation before, we know it's going to be extremely difficult, but you look at the crowd and they're right behind the team, we are a strong unit and that's the challenge we've got ahead."
Another reason for optimism for Martinez has been the form of new signing Jean Beausejour in his first two performances for the club, the winger having moved from Birmingham last week.
"Jean has settled in really well," said the Latics boss. "He's a specialist in the position that he plays and he's been a real boost to the squad.
"I think it'll take a little bit of time to get the benefit of his quality. There are certain situations where he can find a cross where maybe you don't expect it, and I think we'll get that very soon.
"It was pleasing to see such a natural home debut from Jean. It seemed like he's been playing for us for a long time. He's a great character and he's fitted in extremely well with what we want to do."