The monthly sales race has presented a predictable pattern for many months: LEAF, Model S and Volt in the lead, Ford and Toyota plug-ins in the second rank, low-volume and compliance cars way in the back of the pack. So it was quite an upset when a couple of models that everyone had long ago written off leaped ahead to start nipping at the heels of the front-runners.

Total plug-in sales for the month were fairly slow at 9,094, just barely besting the April 2014 numbers. The overall US auto market posted a 5% gain from last year, as trucks and SUVs continued to fly off the lots.

The Tesla Model S held onto the lead it snatched from the LEAF in December, with 1,700 estimated US sales. Deliveries of the D are well underway. The company’s announcement of a new line of stationary storage products also garnered a vast amount of media coverage.

The LEAF soldiered on in second place – April sales of 1,553 were down a bit from March, and far short of the stellar showings of a few months ago.

The action this month was in the second rank, as the Spark EV came out of nowhere to grab third place with 920 units. Most observers have dismissed Chevy’s pure EV as a California compliance car, but for whatever reason, GM decided it wanted to get the little fellows moving, and dropped the MSRP to $25,995 for the base model, while also introducing tempting lease terms of $139 a month. Factoring in federal and state incentives, plus gas savings, residents of California and Oregon – the only two states where the Spark EV is sold – can just about convince themselves that they’re getting a free car. Beginning in the third quarter of 2015, the EV will go on sale in Maryland.

Amazingly, the Spark EV sold more units than the Volt, which saw monthly sales increase to a still-mediocre 905.

In fifth place we find another Cinderella story: the Fiat 500e sold 717 copies in April, according to InsideEVs’ revised method of estimating sales based on Clean Vehicle Rebates claimed in California. Apparently, Californians aren’t listening to Fiat CEO Sergio Marchionne, who has repeatedly ridiculed the cute little hatchback, saying, “I hope you don’t buy it.”

The BMW i3 lost ground this month, as US sales dropped from 922 to 406. EV enthusiasts have high hopes for the i, because it seems to embody the cutting edge of EV technology, as revealed in a series of videos of the high-tech production process.

The jury’s still out on the VW e-Golf. Will it live up to its huge potential, or languish as yet another compliance car? Could April sales surge to 309 units be the beginning of something?

Sources: InsideEVs, Green Car Reports, J.D. Power